IPv4 - Knowledge (XXG)

623: 3891: 1964: 45: 2031:. It provides a vastly increased address space, but also allows improved route aggregation across the Internet, and offers large subnetwork allocations of a minimum of 2 host addresses to end users. However, IPv4 is not directly interoperable with IPv6, so that IPv4-only hosts cannot directly communicate with IPv6-only hosts. With the phase-out of the 3803:(ARP) performs this IP-address-to-hardware-address translation for IPv4. In addition, the reverse correlation is often necessary. For example, unless an address is preconfigured by an administrator, when an IP host is booted or connected to a network it needs to determine its IP address. Protocols for such reverse correlations include 742:, given that it belongs to a class-A network with eight bits for the network mask and 24 bits for the host number. When fewer than four numbers were specified in the address in dotted notation, the last value was treated as an integer of as many bytes as are required to fill out the address to four octets. Thus, the address 2537:

are specified in units of 8 bytes, which is why fragment length must be a multiple of 8. Therefore, the 13-bit field allows a maximum offset of (2 – 1) × 8 = 65,528 bytes, with the header length included (65,528 + 20 = 65,548 bytes), supporting fragmentation of packets exceeding the maximum IP length of 65,535 bytes.

2536:

This field specifies the offset of a particular fragment relative to the beginning of the original unfragmented IP datagram. The fragmentation offset value for the first fragment is always 0. The field is 13 bits wide, so that the offset can be from 0 to 8191 (from (2 – 1) to (2 – 1)). Fragments

1318:

Of the approximately four billion addresses defined in IPv4, about 18 million addresses in three ranges are reserved for use in private networks. Packets addresses in these ranges are not routable in the public Internet; they are ignored by all public routers. Therefore, private hosts cannot directly

2602:

field is used for error checking of the header. When a packet arrives at a router or its destination, the network device calculates the checksum of the header including the checksum field. A value of 0xFFFF is expected. If a different result is obtained, the device discards the packet. Errors in the

2469:

field defines the entire packet size in bytes, including header and data. The minimum size is 20 bytes (header without data) and the maximum is 65,535 bytes. All hosts are required to be able to reassemble datagrams of size up to 576 bytes, but most modern hosts handle much larger packets. Links may

2404:

The IPv4 header is variable in size due to the optional 14th field (options). The IHL field contains the size of the IPv4 header; it has 4 bits that specify the number of 32-bit words in the header. The minimum value for this field is 5, which indicates a length of 5 × 32 bits = 160 bits = 20 bytes.

2671:

by some routers and be blocked. The value in the IHL field must include sufficient extra 32-bit words to hold all options and any padding needed to ensure that the header contains an integral number of 32-bit words. If IHL is greater than 5 (i.e., it is from 6 to 15) it means that the options field

1457:

RFC 3927 defines the special address block 169.254.0.0/16 for link-local addressing. These addresses are only valid on the link (such as a local network segment or point-to-point connection) directly connected to a host that uses them. These addresses are not routable. Like private addresses, these

2484:

This field is an identification field and is primarily used for uniquely identifying the group of fragments of a single IP datagram. Some experimental work has suggested using the ID field for other purposes, such as for adding packet-tracing information to help trace datagrams with spoofed source

782:

networking. The revised system defined five classes. Classes A, B, and C had different bit lengths for network identification. The rest of the address was used as previously to identify a host within a network. Because of the different sizes of fields in different classes, each network class had a

3743:

The receiver identifies matching fragments using the source and destination addresses, the protocol ID, and the identification field. The receiver reassembles the data from fragments with the same ID using both the fragment offset and the more fragments flag. When the receiver receives the last

3662:

bit remains 1 for all the fragments that came with 1 in them and for the last fragment that arrives, it works as usual, that is the MF bit is set to 0 only in the last one. And of course, the Identification field continues to have the same value in all re-fragmented fragments. This way, even if

3262:

The Internet Protocol enables traffic between networks. The design accommodates networks of diverse physical nature; it is independent of the underlying transmission technology used in the link layer. Networks with different hardware usually vary not only in transmission speed, but also in the

3294:

When a router receives a packet, it examines the destination address and determines the outgoing interface to use and that interface's MTU. If the packet size is bigger than the MTU, and the Do not Fragment (DF) bit in the packet's header is set to 0, then the router may fragment the packet.

1971:

In the 1980s, it became apparent that the pool of available IPv4 addresses was depleting at a rate that was not initially anticipated in the original design of the network. The main market forces that accelerated address depletion included the rapidly growing number of Internet users, who

2675:

Since most of the IP options include specifications on how many or which intermediate devices the packet should pass, the IP options are not used for communication over the Internet and IP packets including some of the IP options must be dropped as per IPv4 security assessment

3799:, a network interface can have multiple IP addresses. In order to properly deliver an IP packet to the destination host on a link, hosts and routers need additional mechanisms to make an association between the hardware address of network interfaces and IP addresses. The 3298:

The router divides the packet into fragments. The maximum size of each fragment is the outgoing MTU minus the IP header size (20 bytes minimum; 60 bytes maximum). The router puts each fragment into its own packet, each fragment packet having the following changes:

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It is possible that a packet is fragmented at one router, and that the fragments are further fragmented at another router. For example, a packet of 4,520 bytes, including a 20 bytes IP header is fragmented to two packets on a link with an MTU of 2,500 bytes:

4755:

Special Addresses: In certain contexts, it is useful to have fixed addresses with functional significance rather than as identifiers of specific hosts. When such usage is called for, the address zero is to be interpreted as meaning "this", as in "this

1448:

packets, including their headers containing the private addresses, in a protocol layer during transmission across the public network. Additionally, encapsulated packets may be encrypted for transmission across public networks to secure the data.

2509:

If the DF flag is set, and fragmentation is required to route the packet, then the packet is dropped. This can be used when sending packets to a host that does not have resources to perform reassembly of fragments. It can also be used for

1902:(PtP) link, also called a transit link, is a link that does not have an IP network or subnet number associated with it, but still has an IP address. First introduced in 1993, Phil Karn from Qualcomm is credited as the original designer. 2672:

is present and must be considered. The list of options may be terminated with the option EOOL (End of Options List, 0x00); this is only necessary if the end of the options would not otherwise coincide with the end of the header.

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In the original design of IPv4, an IP address was divided into two parts: the network identifier was the most significant octet of the address, and the host identifier was the rest of the address. The latter was also called the

5818: 2525:

For unfragmented packets, the MF flag is cleared. For fragmented packets, all fragments except the last have the MF flag set. The last fragment has a non-zero Fragment Offset field, differentiating it from an unfragmented

834:, by contrast. CIDR was designed to permit repartitioning of any address space so that smaller or larger blocks of addresses could be allocated to users. The hierarchical structure created by CIDR is managed by the 5803: 2023:

was the first RIR to exhaust its regional pool on 15 April 2011, except for a small amount of address space reserved for the transition technologies to IPv6, which is to be allocated under a restricted policy.

5808: 3748:

flag set to 0, it can calculate the size of the original data payload, by multiplying the last fragment's offset by eight and adding the last fragment's data size. In the given example, this calculation was

1874:

are usually known by names, e.g., www.example.com, not primarily by their IP address, which is used for routing and network interface identification. The use of domain names requires translating, called

1525:. IP packets whose source addresses belong to this network should never appear outside a host. Packets received on a non-loopback interface with a loopback source or destination address must be dropped. 2071:

The IPv4 packet header consists of 14 fields, of which 13 are required. The 14th field is optional and aptly named: options. The fields in the header are packed with the most significant byte first (

3714: 1984:

with IP data services. In addition, high-speed Internet access was based on always-on devices. The threat of exhaustion motivated the introduction of a number of remedial technologies, such as:

1912:. They are used to free IP addresses from a scarce IP address space or to reduce the management of assigning IP and configuration of interfaces. Previously, every link needed to dedicate a 5026: 3371: 3523: 3785: 599:

model, in that it does not guarantee delivery, nor does it assure proper sequencing or avoidance of duplicate delivery. These aspects, including data integrity, are addressed by an

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network has capacity for just two hosts. These networks are typically used for point-to-point connections. There is no network identifier or broadcast address for these networks.

2011:

By the mid-1990s, NAT was used pervasively in network access provider systems, along with strict usage-based allocation policies at the regional and local Internet registries.

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Since two private networks, e.g., two branch offices, cannot directly interoperate via the public Internet, the two networks must be bridged across the Internet via a

1752:

In the past, conflict between network addresses and broadcast addresses arose because some software used non-standard broadcast addresses with zeros instead of ones.

1838:

In red, is shown the host part of the IP address; the other part is the network prefix. The host gets inverted (logical NOT), but the network prefix remains intact.

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In red, is shown the host part of the IP address; the other part is the network prefix. The host gets inverted (logical NOT), but the network prefix remains intact.

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sends messages with adjusted TTL values and uses these ICMP time exceeded messages to identify the routers traversed by packets from the source to the destination.

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combines the address with its routing prefix in a compact format, in which the address is followed by a slash character (/) and the count of leading consecutive

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publication RFC 791 (September 1981), replacing an earlier definition of January 1980 (RFC 760). In March 1982, the US Department of Defense decided on the

5813: 588:, which is the forwarding of packets from a source host to the next router that is one hop closer to the intended destination host on another network. 2015:

The primary address pool of the Internet, maintained by IANA, was exhausted on 3 February 2011, when the last five blocks were allocated to the five

3787:

bytes. When the receiver has all fragments, they can be reassembled in the correct sequence according to the offsets to form the original datagram.

2668: 2079:). The most significant bit is numbered 0, so the version field is actually found in the four most significant bits of the first byte, for example. 1458:

addresses cannot be the source or destination of packets traversing the internet. These addresses are primarily used for address autoconfiguration (

2614:

When a packet arrives at a router, the router decreases the TTL field in the header. Consequently, the router must calculate a new header checksum.

3829: 2020: 5030: 2621:

of the ones' complement sum of all 16-bit words in the header. For purposes of computing the checksum, the value of the checksum field is zero.

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2016 IEEE International Conference on Emerging Technologies and Innovative Business Practices for the Transformation of Societies (EmergiTech)

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consists of a header section and a data section. An IP packet has no data checksum or any other footer after the data section. Typically the

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Earlier versions of TCP/IP were a combined specification through TCP/IPv3. With IPv4, the Internet Protocol became a separate specification.

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A three-bit field follows and is used to control or identify fragments. They are (in order, from most significant to least significant):

3804: 1899: 835: 161: 3175: 2408: 408: 351: 276: 2405:

As a 4-bit field, the maximum value is 15; this means that the maximum size of the IPv4 header is 15 × 32 bits = 480 bits = 60 bytes.

5833: 5254: 3162: 418: 388: 3136:

The packet payload is not included in the checksum. Its contents are interpreted based on the value of the Protocol header field.

2563:, the router decrements the TTL field by one. When the TTL field hits zero, the router discards the packet and typically sends an 2455:. ECN is an optional feature available when both endpoints support it and effective when also supported by the underlying network. 5838: 5093: 2435: 472: 403: 196: 1025:

between two hosts on a single link when no IP address is otherwise specified, such as would have normally been retrieved from a

545:

address space which provides 4,294,967,296 (2) unique addresses, but large blocks are reserved for special networking purposes.

5760: 5002: 4623: 4420: 4362: 4266: 4022: 2391: 2052: 1879:, them to addresses and vice versa. This is analogous to looking up a phone number in a phone book using the recipient's name. 1470: 855: 2555:. It is specified in seconds, but time intervals less than 1 second are rounded up to 1. In practice, the field is used as a 2474:. Fragmentation in IPv4 is performed in either the sending host or in routers. Reassembly is performed at the receiving host. 1988: 1337: 815: 221: 211: 3908: 3321:

field is set, based on the offset of the fragment in the original data payload. This is measured in units of 8-byte blocks.

3188: 2608: 604: 341: 321: 271: 3669: 5056: 1660:

However, this does not mean that every address ending in 0 or 255 cannot be used as a host address. For example, in the

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different capacity for addressing hosts. In addition to the three classes for addressing hosts, Class D was defined for

592: 261: 256: 251: 5249:. Piscataway, NJ: University of Technology, Mauritius, Institute of Electrical and Electronics Engineers. August 2016. 5828: 3800: 3139: 2636: 2585: 2304: 2000: 1320: 622: 438: 398: 266: 5734: 3282:, the next generation of the Internet Protocol, does not allow routers to perform fragmentation; hosts must perform 670:

IPv4 addresses may be represented in any notation expressing a 32-bit integer value. They are most often written in

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The long-term solution to address exhaustion was the 1998 specification of a new version of the Internet Protocol,

2016: 1977: 1445: 839: 584:

of the Internet Protocol Suite. In essence it forms the Internet. It uses a logical addressing system and performs

3335: 3332:

For example, for an MTU of 1,500 bytes and a header size of 20 bytes, the fragment offsets would be multiples of

3264: 2664: 2515: 2040: 1534: 964: 3487: 3227: 291: 231: 1257:

Assigned as MCAST-TEST-NET, documentation and examples (Note that this is part of the above multicast space.)

3752: 2754:

Indicates the size of the entire option (including this field). This field may not exist for simple options.

5378: 4945: 3824: 2425: 2035:

experimental network starting in 2004, permanent formal deployment of IPv6 commenced in 2006. Completion of

1958: 1949:

One of the disadvantages of unnumbered interfaces is that it is harder to do remote testing and management.

1543:. To avoid ambiguity in representation, this address is reserved. The last address has all host bits set to 1437: 561: 458: 448: 241: 156: 140: 771:. This structure permitted a maximum of 256 network identifiers, which was quickly found to be inadequate. 3201: 2604: 326: 176: 4885: 859: 627: 453: 226: 1539:

The first address in a subnet is used to identify the subnet itself. In this address all host bits are

798:. This division was made more flexible with the introduction of variable-length subnet masks (VLSM) in 3890: 3663:

fragments are re-fragmented, the receiver knows they have initially all started from the same packet.

1462:) when a host cannot obtain an IP address from a DHCP server or other internal configuration methods. 5645: 5567: 5456: 5398: 5340: 5299: 5221: 5139: 5078: 4965: 4920: 4864: 4790: 4734: 4685: 4645: 4583: 4522: 4480: 4434: 4384: 4330: 4288: 4226: 4086: 3528:

When forwarded to a link with an MTU of 1,500 bytes, each fragment is fragmented into two fragments:

2599: 2004: 819: 671: 600: 596: 236: 124: 3724:

A receiver knows that a packet is a fragment, if at least one of the following conditions is true:

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contains a complete list of payload protocol types. Some of the common payload protocols include:

2043:

are necessary to permit hosts to participate in the Internet using both versions of the protocol.

4185: 4133: 3945: 3808: 3283: 2564: 2560: 2511: 2448: 2072: 1906: 1883: 1865: 1022: 443: 171: 5714: 3795:

IP addresses are not tied in any permanent manner to networking hardware and, indeed, in modern

2075:), and for the diagram and discussion, the most significant bits are considered to come first ( 1963: 5559: 5260: 5250: 4710: 4665: 4637: 4575: 4376: 4280: 4078: 3937: 3929: 2584:

This field defines the protocol used in the data portion of the IP datagram. IANA maintains a

2093: 1548: 1474: 1302: 968: 675: 507: 371: 147: 5775: 5635: 5549: 5518: 5446: 5388: 5330: 5289: 5279: 5211: 5129: 4955: 4910: 4854: 4780: 4724: 4675: 4627: 4565: 4512: 4470: 4424: 4366: 4320: 4270: 4216: 4068: 3953: 3919: 3796: 3268: 3267:(MTU). When one network wants to transmit datagrams to a network with a smaller MTU, it may 3257: 2677: 2471: 1973: 1352: 996: 807: 799: 791: 719: 565: 531: 3464:

The total data size is preserved: 2,480 bytes + 2,020 bytes = 4,500 bytes. The offsets are

2514:, either automatically by the host IP software, or manually using diagnostic tools such as 774:

To overcome this limit, the most-significant address octet was redefined in 1981 to create

5764: 2421: 2060: 2036: 655: 519: 511: 312: 66: 3849: 2778:

column is derived from the Copied, Option Class, and Option Number bits as defined above.

1465:

When the address block was reserved, no standards existed for address autoconfiguration.

1171:

Used for benchmark testing of inter-network communications between two separate subnets

5384:

Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers

4154: 3467: 3272: 1934:

subnet using 2 or 4 IP addresses per point-to-point link. When a link is unnumbered, a

1551:

for sending messages to all devices on the subnet simultaneously. For networks of size

790:

Dividing existing classful networks into subnets began in 1985 with the publication of

581: 510:(IP) as a standalone specification. It is one of the core protocols of standards-based 362: 36: 5788: 5097: 3998: 1886:(DNS), a hierarchical, distributed naming system that allows for the subdelegation of 5823: 5797: 5119: 3949: 2713:

Set to 1 if the options need to be copied into all fragments of a fragmented packet.

2603:

data portion of the packet are handled separately by the encapsulated protocol. Both

2429: 708: 635: 117: 5757: 3655:

Again, the data size is preserved: 1,480 + 1,000 = 2,480, and 1,480 + 540 = 2,020.

2650: 2632: 2552: 2548: 2059:

encapsulates IP packets in frames with a CRC footer that detects most errors, many

1235: 1124: 866:

traffic and to provide addressing space for unrestricted uses on private networks.

577: 281: 5052: 4209:

Y. Rekhter; B. Moskowitz; D. Karrenberg; G. J. de Groot; E. Lear (February 1996).

1766:, broadcast addresses do not necessarily end with 255. For example, a CIDR subnet 1733:

is the network identifier and must not be assigned to an interface. The addresses

5587: 5583: 5570: 5539: 5492: 5488: 5484: 5476: 5472: 5468: 5459: 5440: 5426: 5422: 5418: 5414: 5410: 5401: 5382: 5364: 5360: 5356: 5302: 5283: 5233: 5224: 5205: 5191: 5187: 5183: 5179: 5175: 5171: 5167: 5163: 5159: 5155: 5151: 5142: 5123: 4989: 4985: 4981: 4977: 4968: 4949: 4932: 4923: 4904: 4867: 4848: 4834: 4830: 4826: 4822: 4818: 4814: 4810: 4806: 4802: 4793: 4774: 4697: 4688: 4669: 4648: 4617: 4603: 4599: 4595: 4586: 4555: 4538: 4534: 4525: 4506: 4492: 4483: 4464: 4450: 4446: 4437: 4414: 4396: 4387: 4356: 4333: 4314: 4300: 4291: 4260: 4246: 4242: 4238: 4229: 4210: 4114: 4110: 4106: 4102: 4098: 4089: 4058: 3874: 2681: 2551:

field limits a datagram's lifetime to prevent network failure in the event of a

2470:

impose further restrictions on the packet size, in which case datagrams must be

2452: 2428:(DiffServ). Real-time data streaming makes use of the DSCP field. An example is 1981: 1709:. One can use the following addresses for hosts, even though they end with 255: 811: 803: 702: 5701: 5697: 5693: 5689: 5685: 5681: 5677: 5673: 5669: 5665: 5661: 5657: 5648: 5629: 5601: 5579: 5480: 5352: 5343: 5320: 4750: 4746: 4737: 4718: 3897: 1595:

is used to refer to the entire subnet. The broadcast address of the network is

967:

for communications between a service provider and its subscribers when using a

795: 129: 5625: 5316: 4770: 4714: 3941: 3666:

The last offset and last data size are used to calculate the total data size:

2519: 2056: 616: 429: 5563: 5264: 4641: 4579: 4380: 4284: 4082: 3933: 3275:

and is performed in IPv4 routers limiting exposure to these issues by hosts.

17: 4259:

J. Weil; V. Kuarsingh; C. Donley; C. Liljenstolpe; M. Azinger (April 2012).

3957: 3924: 2556: 1887: 1494: 1466: 1441: 863: 784: 683: 659: 112: 44: 4616:

S. Venaas; R. Parekh; G. Van de Velde; T. Chown; M. Eubanks (August 2012).

5523: 5506: 5079:"Five /8s allocated to RIRs – no unallocated IPv4 unicast /8s remain" 3314:(MF) flag is set for all fragments except the last one, which is set to 0. 3870: 3866: 3853: 1939: 1909: 1871: 1522: 1459: 723: 515: 3974: 1882:

The translation between addresses and domain names is performed by the

1074: 698: 679: 527: 5780: 5640: 5554: 5451: 5393: 5335: 5294: 5216: 5134: 4960: 4915: 4859: 4785: 4729: 4680: 4632: 4570: 4517: 4475: 4429: 4371: 4325: 4275: 4221: 4073: 2466: 658:(2 + 2 + 2 ≈ 18 million addresses) and 542: 523: 392: 286: 185: 165: 5819:

Knowledge (XXG) articles published in peer-reviewed literature (J2W)

626:

Decomposition of the quad-dotted IPv4 address representation to its

5789:

Official current state of IPv4/8 allocations, as maintained by IANA

2765:

Option-specific data. This field may not exist for simple options.

2394:

is the four-bit version field. For IPv4, this is always equal to 4.

2687:

The possible options that can be put in the header are as follows:

2032: 1962: 843: 621: 413: 191: 77: 5322:

INTERNET PROTOCOL - DARPA INTERNET PROGRAM PROTOCOL SPECIFICATION

4179:"Understanding IP Addressing: Everything You Ever Wanted To Know" 4057:

M. Cotton; L. Vegoda; B. Haberman (April 2013). R. Bonica (ed.).

1938:

is used, a single IP address borrowed from a defined (normally a

1473:(APIPA), which was deployed on millions of machines and became a 846:

database that provides information about IP address assignments.

5545: 5326: 4561: 4064: 3812: 3279: 3214: 2684:, since they can expose the network topology or network details. 2076: 2028: 1478: 1120: 1116: 1026: 557: 535: 522:

networks. IPv4 was the first version deployed for production on

381: 346: 296: 216: 181: 105: 4129:"Vint Cerf - We Still Have 80 Per Cent of the World to Connect" 576:

The Internet Protocol is the protocol that defines and enables

5804:

Knowledge (XXG) articles published in peer-reviewed literature

4847:

A. Retana; R. White; V. Fuller; D. McPherson (December 2000).

2115: 201: 5285:

Technical Criteria for Choosing IP The Next Generation (IPng)

4671:

Assigned Numbers: RFC 1700 is Replaced by an On-line Database

3739:

is nonzero, which is true for all fragments except the first.

2635:

of the sender of the packet. It may be changed in transit by

787:

addressing and Class E was reserved for future applications.

689:

For example, the quad-dotted IP address in the illustration (

5809:

Knowledge (XXG) articles published in WikiJournal of Science

5442:

The Addition of Explicit Congestion Notification (ECN) to IP

2039:

is expected to take considerable time, so that intermediate

3895:

This article was adapted from the following source under a

862:

for special purposes. Notably these addresses are used for

5092:

Asia-Pacific Network Information Centre (15 April 2011).

5003:"Understanding and Configuring the ip unnumbered Command" 4508:

Benchmarking Methodology for Network Interconnect Devices

2653:

of the receiver of the packet. It may be affected by NAT.

858:(IETF) and IANA have restricted from general use various 5704:.Obsoletes IENs: 127, 117, 93. 3732:

is set, which is true for all fragments except the last.

3271:

its datagrams. In IPv4, this function was placed at the

2774:

The table below shows the defined options for IPv4. The

5751: 4776:

Requirements for Internet Hosts -- Communication Layers

3902: 1149:

Used for local communications within a private network

1054:

Used for local communications within a private network

939:

Used for local communications within a private network

5439:

K. Ramakrishnan; S. Floyd; D. Black (September 2001).

4557:

IANA Guidelines for IPv4 Multicast Address Assignments

718:

Other address representations were in common use when

4884:

Almquist, Philip; Kastenholz, Frank (December 1993).

4416:

Deprecating the Anycast Prefix for 6to4 Relay Routers

3755: 3672: 3490: 3470: 3338: 2432:(VoIP), which is used for interactive voice services. 1562:

or larger, the broadcast address always ends in 255.

818:(CIDR), which expressed the number of bits (from the 1972:

increasingly used mobile computing devices, such as

3709:{\displaystyle 495\times 8+540=3{,}960+540=4{,}500} 1209:Assigned as TEST-NET-3, documentation and examples 1190:Assigned as TEST-NET-2, documentation and examples 1096:Assigned as TEST-NET-1, documentation and examples 123: 111: 101: 83: 73: 62: 54: 4903:P. Almquist (November 1994). F. Kastenholz (ed.). 4850:Using 31-Bit Prefixes on IPv4 Point-to-Point Links 4316:Dynamic Configuration of IPv4 Link-Local Addresses 4262:IANA-Reserved IPv4 Prefix for Shared Address Space 3779: 3708: 3517: 3476: 3365: 2063:carried by IP also have their own error checking. 1483:Dynamic Configuration of IPv4 Link-Local Addresses 5767:— IP Header Breakdown, including specific options 5125:Internet Protocol, Version 6 (IPv6) Specification 2611:have separate checksums that apply to their data. 1282:Reserved for future use (former Class E network) 842:(RIRs). Each RIR maintains a publicly searchable 662:addresses (2 ≈ 268 million addresses). 5346:. IEN 128, 123, 111, 80, 54, 44, 41, 28, 26. 5207:6bone (IPv6 Testing Address Allocation) Phaseout 3909:"A Survey on Internet Protocol version 4 (IPv4)" 1997:removed the need for addresses on transit links. 1749:, etc., may be assigned, despite ending with 0. 1481:defined a formal standard in RFC 3927, entitled 530:in January 1983. It is still used to route most 5735:"Internet Protocol Version 4 (IPv4) Parameters" 5278:Partridge, C.; Kastenholz, F. (December 1994). 4355:J. Arkko; M. Cotton; L. Vegoda (January 2010). 4358:IPv4 Address Blocks Reserved for Documentation 4313:S. Cheshire; B. Aboba; E. Guttman (May 2005). 3907:Michel Bakni; Sandra Hanbo (9 December 2022). 2485:addresses, but any such use is now prohibited. 1319:communicate with public networks, but require 5051:Smith, Lucie; Lipner, Ian (3 February 2011). 4554:M. Cotton; L. Vegoda; D. Meyer (March 2010). 2447:This field allows end-to-end notification of 480: 8: 5507:"Practical network support for IP traceback" 4023:"IANA IPv4 Special-Purpose Address Registry" 634:IPv4 uses 32-bit addresses which limits the 556:Internet Protocol version 4 is described in 30: 5027:"World 'running out of Internet addresses'" 3852:joke, proposed for use in RFC 3514 as the " 3366:{\displaystyle {\frac {1{,}500-20}{8}}=185} 2669:some options may be considered as dangerous 1685:, which is equivalent to the address range 534:today, even with the ongoing deployment of 5541:Updated Specification of the IPv4 ID Field 5094:"APNIC IPv4 Address Pool Reaches Final /8" 5053:"Free Pool of IPv4 Address Space Depleted" 4765: 4763: 4549: 4547: 4350: 4348: 4346: 3518:{\displaystyle {\frac {0+2{,}480}{8}}=310} 870: 778:, in a system which later became known as 715:bits in the routing prefix (subnet mask). 564:(TCP/IP) as the standard for all military 487: 473: 136: 29: 5779: 5639: 5553: 5522: 5511:ACM SIGCOMM Computer Communication Review 5450: 5392: 5334: 5293: 5215: 5133: 4959: 4914: 4858: 4784: 4728: 4679: 4631: 4569: 4516: 4474: 4428: 4370: 4324: 4274: 4220: 4204: 4202: 4200: 4198: 4072: 4052: 4050: 4048: 4046: 4044: 4042: 3923: 3754: 3671: 3491: 3489: 3469: 3339: 3337: 1994: 678:of the address expressed individually in 654:IPv4 reserves special address blocks for 4466:An Anycast Prefix for 6to4 Relay Routers 4212:Address Allocation for Private Internets 3530: 3379: 3144: 2783: 2692: 2341: 2081: 1790: 1605: 1327: 830:, and the class-based scheme was dubbed 615:For broader coverage of this topic, see 3966: 3841: 3830:List of assigned /8 IPv4 address blocks 3780:{\displaystyle 495\times 8+540=4{,}500} 1428:Contiguous range of 256 Class C blocks 1323:at a routing gateway for this purpose. 428: 361: 311: 146: 139: 27:Fourth version of the Internet Protocol 2667:is not often used. Packets containing 2354: 1406:Contiguous range of 16 Class B blocks 806:in 1987. In 1993, based on this work, 4951:Requirements for IP Version 4 Routers 4886:"Towards Requirements for IP Routers" 4619:Multicast Addresses for Documentation 4505:S. Bradner; J. McQuaid (March 1999). 4060:Special-Purpose IP Address Registries 2724:A general options category. 0 is for 1477:. Many years later, in May 2005, the 1329:Reserved private IPv4 network ranges 7: 3241:Stream Control Transmission Protocol 2311: 2282: 1946:can be used on multiple interfaces. 1905:The purpose of a transit link is to 5752:Internet Assigned Numbers Authority 4906:Towards Requirements for IP Routers 3869:networking technologies, including 3805:Dynamic Host Configuration Protocol 2326: 2268: 1991:(CIDR), for smaller ISP allocations 836:Internet Assigned Numbers Authority 5288:. p. 26. sec. 6.2. 3176:Internet Group Management Protocol 2409:Differentiated Services Code Point 25: 5814:Externally peer reviewed articles 5204:R. Fink; R. Hinden (March 2004). 3163:Internet Control Message Protocol 2787:Option Type (decimal/hexadecimal) 2617:The checksum field is the 16-bit 2253: 1469:created an implementation called 5602:"Fragment Offset - IP With Ease" 3889: 2559:—when the datagram arrives at a 2436:Explicit Congestion Notification 2390:The first header field in an IP 1967:IPv4 address exhaustion timeline 914:Current (local, "this") network 722:was practiced. For example, the 603:transport protocol, such as the 43: 5600:Bhardwaj, Rashmi (2020-06-04). 4890:Internet Engineering Task Force 4624:Internet Engineering Task Force 4421:Internet Engineering Task Force 4363:Internet Engineering Task Force 4267:Internet Engineering Task Force 3373:(0, 185, 370, 555, 740, etc.). 2003:(NAT) removed the need for the 1825:11001011.00000000.01110001.0001 1809:11001011.00000000.01110001.0001 1529:First and last subnet addresses 1471:Automatic Private IP Addressing 856:Internet Engineering Task Force 2980:Commercial IP Security Option 2498:bit 0: Reserved; must be zero. 1989:Classless Inter-Domain Routing 816:Classless Inter-Domain Routing 506:) is the first version of the 1: 5122:; R. Hinden (December 1998). 3189:Transmission Control Protocol 3068:Selective Directed Broadcast 1417:192.168.0.0 – 192.168.255.255 605:Transmission Control Protocol 5772:IP Mobility Support for IPv4 5381:; D. Black (December 1998). 5057:Number Resource Organization 3873:, the hardware address is a 3252:Fragmentation and reassembly 3013:Experimental Access Control 2424:(ToS), this field specifies 2399:Internet Header Length (IHL) 2356: 2225: 1179:198.51.100.0–198.51.100.255 1135:192.168.0.0–192.168.255.255 1115:Reserved. Formerly used for 1007:169.254.0.0–169.254.255.255 840:regional Internet registries 701:number 2886794753, which in 595:protocol, and operates on a 3811:(BOOTP) and, infrequently, 3801:Address Resolution Protocol 3307:field is the fragment size. 3140:List of IP protocol numbers 3035:Extended Internet Protocol 2637:network address translation 2586:list of IP protocol numbers 2001:Network address translation 1978:personal digital assistants 1701:, the broadcast address is 1640:11000000.10101000.00000101. 1624:11000000.10101000.00000101. 1565:For example, in the subnet 1419: 1394: 1392:172.16.0.0 – 172.31.255.255 1369: 1321:network address translation 1292: 1267: 1248: 1219: 1200: 1181: 1159: 1137: 1106: 1087: 1073:IETF Protocol Assignments, 1064: 1039: 1009: 980: 949: 947:100.64.0.0–100.127.255.255 924: 899: 536:Internet Protocol version 6 500:Internet Protocol version 4 89:; 43 years ago 31:Internet Protocol version 4 5855: 5590:. 5538:J. Touch (February 2013). 5495:. 5429:. 5367:. 5236:. 5194:. 5077:ICANN,nanog mailing list. 4992:. 4935:. 4837:. 4700:. 4606:. 4541:. 4495:. 4453:. 4399:. 4303:. 4249:. 4117:. 3286:before sending datagrams. 3255: 3112:Experimental Flow Control 3090:Upstream Multicast Packet 2969:Extended Security (RIPSO) 2504:bit 2: More Fragments (MF) 2501:bit 1: Don't Fragment (DF) 2420:Originally defined as the 2339: 2324: 2309: 2280: 2275: 2266: 2251: 1956: 1863: 1780:has the broadcast address 1532: 1492: 1301:Reserved for the "limited 1265:240.0.0.0–255.255.255.254 1246:233.252.0.0–233.252.0.255 1217:224.0.0.0–239.255.255.255 1198:203.0.113.0–203.0.113.255 1157:198.18.0.0–198.19.255.255 1104:192.88.99.0–192.88.99.255 1037:172.16.0.0–172.31.255.255 978:127.0.0.0–127.255.255.255 614: 5634:. Network Working Group. 5445:. Network Working Group. 5387:. Network Working Group. 5210:. Network Working Group. 5128:. Network Working Group. 4954:. Network Working Group. 4909:. Network Working Group. 4853:. Network Working Group. 4779:. Network Working Group. 4723:. Network Working Group. 4674:. Network Working Group. 4511:. Network Working Group. 4469:. Network Working Group. 4319:. Network Working Group. 4215:. Network Working Group. 4155:"A Brief History of IPv4" 3265:maximum transmission unit 3123:RFC3692-style Experiment 3101:RFC3692-style Experiment 2936:RFC3692-style Experiment 2903:RFC3692-style Experiment 2848:Experimental Measurement 2730:debugging and measurement 2649:This 32-bit field is the 2631:This 32-bit field is the 2302: 2295: 2273: 2244: 2239: 2237: 2230: 2223: 2106: 2103: 2100: 2097: 2061:transport-layer protocols 1836: 1755:In networks smaller than 1651: 1535:IPv4 subnetting reference 1367:10.0.0.0 – 10.255.255.255 1238:(former Class D network) 682:numbers and separated by 674:, which consists of four 42: 35: 5834:Internet layer protocols 5319:, ed. (September 1981). 5280:"6.2 IP Header Checksum" 4463:C. Huitema (June 2001). 3744:fragment, which has the 3228:Open Shortest Path First 2732:. 1 and 3 are reserved. 2297: 2246: 2232: 1953:Address space exhaustion 1547:. It is used as a local 922:10.0.0.0–10.255.255.255 734:was commonly written as 697:) represents the 32-bit 5839:Network layer protocols 5505:Savage, Stefan (2000). 3825:History of the Internet 3658:Also in this case, the 3024:IMI Traffic Descriptor 2426:differentiated services 2041:transition technologies 1959:IPv4 address exhaustion 1438:virtual private network 872:Special address blocks 666:Address representations 562:Internet Protocol Suite 538:(IPv6), its successor. 141:Internet protocol suite 5715:"Cisco unofficial FAQ" 5656:Obsoleted by RFC 5483:. Updated by RFC 5417:. Updated by RFC 5377:K. Nichols; S. Blake; 5355:. Updated by RFC 5158:. Updated by RFC 5150:Obsoleted by RFC 4984:. Updated by RFC 4931:Obsoleted by RFC 4773:, ed. (October 1989). 4745:Obsoleted by RFC 4668:, ed. (January 2002). 4491:Obsoleted by RFC 4443:Best Current Practice. 4245:. Updated by RFC 4184:. 3Com. Archived from 4113:. Updated by RFC 3975:"BGP Analysis Reports" 3916:WikiJournal of Science 3781: 3710: 3519: 3478: 3367: 3202:User Datagram Protocol 2728:options, and 2 is for 2567:message to the sender. 1968: 1942:) interface. The same 1890:to other DNS servers. 1305:" destination address 1085:192.0.2.0–192.0.2.255 1062:192.0.0.0–192.0.0.255 897:0.0.0.0–0.255.255.255 705:format is 0xAC10FE01. 631: 5758:IP, Internet Protocol 5660:. Obsoletes RFC 5524:10.1145/347057.347560 5154:. Obsoletes RFC 4749:. Obsoletes RFC 4592:Best Common Practice. 4533:Updated by: RFC 4409:O. Troan (May 2015). 4297:Best Common Practice. 4235:Best Common Practice. 4095:Best Common Practice. 3925:10.15347/WJS/2022.002 3782: 3711: 3520: 3479: 3368: 3079:Dynamic Packet State 2743:Specifies an option. 1995:Unnumbered interfaces 1966: 1845:As a special case, a 1800:Dot-decimal notation 1615:Dot-decimal notation 1453:Link-local addressing 1168:Private network 1070:Private network 1051:Private network 961:Private network 936:Private network 860:reserved IP addresses 850:Special-use addresses 625: 5349:Internet Standard 5. 4801:Updated by RFC 4799:Internet Standard 3. 3753: 3670: 3488: 3468: 3336: 3328:field is recomputed. 3002:Strict Source Route 2600:IPv4 header checksum 2005:end-to-end principle 1894:Unnumbered interface 1499:The class A network 1023:link-local addresses 965:Shared address space 883:Number of addresses 822:) as, for instance, 672:dot-decimal notation 597:best-effort delivery 5471:. Updates RFC 5467:Obsoletes RFC 5409:Obsoletes RFC 5351:Obsoletes RFC 5232:Obsoletes RFC 4976:Obsoletes RFC 4948:, ed. (June 1995). 4696:Obsoletes RFC 4602:. Updates RFC 4594:Obsoletes RFC 4445:Obsoletes RFC 4237:Obsoletes RFC 4097:Obsoletes RFC 3791:Assistive protocols 2958:Loose Source Route 2826:Security (defunct) 2804:End of Option List 2644:Destination address 2342:Destination address 2084: 2083:IPv4 header format 2077:MSB 0 bit numbering 1507:(classless network 1330: 1287:255.255.255.255/32 873: 720:classful networking 566:computer networking 526:in 1982 and on the 32: 5829:Internet Standards 5763:2011-05-14 at the 5628:(September 1981). 5576:Proposed Standard. 5465:Proposed Standard. 5407:Proposed Standard. 4974:Proposed Standard. 4873:Proposed Standard. 4339:Proposed Standard. 4134:The New York Times 3809:Bootstrap Protocol 3777: 3706: 3515: 3474: 3363: 3284:Path MTU Discovery 3215:IPv6 encapsulation 3046:Address Extension 2565:ICMP time exceeded 2542:Time to live (TTL) 2512:path MTU discovery 2449:network congestion 2082: 2073:network byte order 1969: 1884:Domain Name System 1866:Domain Name System 1860:Address resolution 1821:Broadcast address 1636:Broadcast address 1521:) is reserved for 1328: 999:to the local host 997:loopback addresses 871: 632: 5578:Updates RFC 4395:Updates RFC 4299:Updates RFC 4191:on June 16, 2001. 4159:IPv4 Market Group 3797:operating systems 3653: 3652: 3569: 3555: 3548: 3541: 3507: 3477:{\displaystyle 0} 3462: 3461: 3418: 3404: 3397: 3390: 3355: 3249: 3248: 3127: 3126: 2947:Security (RIPSO) 2769: 2768: 2380: 2379: 1843: 1842: 1839: 1658: 1657: 1654: 1587:) the identifier 1549:broadcast address 1475:de facto standard 1432: 1431: 1309: 1308: 969:carrier-grade NAT 750:is equivalent to 508:Internet Protocol 497: 496: 148:Application layer 135: 134: 16:(Redirected from 5846: 5785: 5783: 5739: 5738: 5731: 5725: 5724: 5722: 5721: 5711: 5705: 5652: 5643: 5641:10.17487/RFC0790 5631:ASSIGNED NUMBERS 5622: 5616: 5615: 5613: 5612: 5597: 5591: 5574: 5557: 5555:10.17487/RFC6864 5535: 5529: 5528: 5526: 5502: 5496: 5463: 5454: 5452:10.17487/RFC3168 5436: 5430: 5405: 5396: 5394:10.17487/RFC2474 5374: 5368: 5347: 5338: 5336:10.17487/RFC0791 5313: 5307: 5306: 5297: 5295:10.17487/RFC1726 5275: 5269: 5268: 5243: 5237: 5228: 5219: 5217:10.17487/RFC3701 5201: 5195: 5146: 5137: 5135:10.17487/RFC2460 5116: 5110: 5109: 5107: 5105: 5100:on 7 August 2011 5096:. Archived from 5089: 5083: 5082: 5074: 5068: 5067: 5065: 5063: 5048: 5042: 5041: 5039: 5038: 5029:. Archived from 5023: 5017: 5016: 5014: 5013: 4999: 4993: 4972: 4963: 4961:10.17487/RFC1812 4942: 4936: 4927: 4918: 4916:10.17487/RFC1716 4900: 4894: 4893: 4881: 4875: 4871: 4862: 4860:10.17487/RFC3021 4844: 4838: 4797: 4788: 4786:10.17487/RFC1122 4767: 4758: 4741: 4732: 4730:10.17487/RFC0923 4720:ASSIGNED NUMBERS 4717:(October 1984). 4707: 4701: 4692: 4683: 4681:10.17487/RFC3232 4662: 4656: 4652: 4635: 4633:10.17487/RFC6676 4613: 4607: 4590: 4573: 4571:10.17487/RFC5771 4551: 4542: 4529: 4520: 4518:10.17487/RFC2544 4502: 4496: 4487: 4478: 4476:10.17487/RFC3068 4460: 4454: 4441: 4432: 4430:10.17487/RFC7526 4406: 4400: 4391: 4374: 4372:10.17487/RFC5737 4352: 4341: 4337: 4328: 4326:10.17487/RFC3927 4310: 4304: 4295: 4278: 4276:10.17487/RFC6598 4256: 4250: 4233: 4224: 4222:10.17487/RFC1918 4206: 4193: 4192: 4190: 4183: 4175: 4169: 4168: 4166: 4165: 4151: 4145: 4144: 4142: 4141: 4124: 4118: 4093: 4076: 4074:10.17487/RFC6890 4054: 4037: 4036: 4034: 4033: 4019: 4013: 4012: 4010: 4009: 3995: 3989: 3988: 3986: 3985: 3971: 3962: 3961: 3927: 3913: 3900: 3893: 3878: 3863: 3857: 3846: 3786: 3784: 3783: 3778: 3715: 3713: 3712: 3707: 3567: 3553: 3546: 3539: 3531: 3524: 3522: 3521: 3516: 3508: 3503: 3492: 3483: 3481: 3480: 3475: 3416: 3402: 3395: 3388: 3380: 3372: 3370: 3369: 3364: 3356: 3351: 3340: 3258:IP fragmentation 3145: 2784: 2693: 2660: 2659: 2646: 2645: 2628: 2627: 2619:ones' complement 2595: 2594: 2581: 2580: 2544: 2543: 2533: 2532: 2492: 2491: 2481: 2480: 2462: 2461: 2453:dropping packets 2443: 2442: 2416: 2415: 2401: 2400: 2387: 2386: 2085: 2047:Packet structure 1974:laptop computers 1932: 1931: 1928: 1921: 1920: 1917: 1854: 1853: 1850: 1837: 1829: 1828: 1813: 1812: 1791: 1786: 1785: 1778: 1777: 1774: 1771: 1764: 1763: 1760: 1747: 1746: 1739: 1738: 1731: 1730: 1723: 1722: 1715: 1714: 1707: 1706: 1699: 1698: 1691: 1690: 1683: 1682: 1679: 1676: 1669: 1668: 1665: 1652: 1644: 1643: 1628: 1627: 1606: 1601: 1600: 1593: 1592: 1585: 1584: 1577: 1576: 1573: 1570: 1560: 1559: 1556: 1519: 1518: 1515: 1512: 1505: 1504: 1425: 1424: 1403: 1402: 1399: 1378: 1377: 1374: 1331: 1314:Private networks 1295: 1290:255.255.255.255 1276: 1275: 1272: 1251: 1228: 1227: 1224: 1203: 1184: 1176:198.51.100.0/24 1165: 1164: 1146:Private network 1143: 1142: 1119:relay (included 1109: 1090: 1067: 1048: 1047: 1044: 1015: 1014: 989: 988: 985: 958: 957: 954: 933: 932: 929: 908: 907: 904: 874: 828: 827: 820:most significant 756: 755: 748: 747: 740: 739: 732: 731: 695: 694: 656:private networks 650: 649: 646: 643: 532:Internet traffic 489: 482: 475: 137: 97: 95: 90: 47: 33: 21: 5854: 5853: 5849: 5848: 5847: 5845: 5844: 5843: 5794: 5793: 5770: 5765:Wayback Machine 5748: 5743: 5742: 5733: 5732: 5728: 5719: 5717: 5713: 5712: 5708: 5624: 5623: 5619: 5610: 5608: 5599: 5598: 5594: 5537: 5536: 5532: 5504: 5503: 5499: 5438: 5437: 5433: 5376: 5375: 5371: 5315: 5314: 5310: 5277: 5276: 5272: 5257: 5245: 5244: 5240: 5203: 5202: 5198: 5118: 5117: 5113: 5103: 5101: 5091: 5090: 5086: 5076: 5075: 5071: 5061: 5059: 5050: 5049: 5045: 5036: 5034: 5025: 5024: 5020: 5011: 5009: 5001: 5000: 4996: 4944: 4943: 4939: 4902: 4901: 4897: 4883: 4882: 4878: 4846: 4845: 4841: 4769: 4768: 4761: 4709: 4708: 4704: 4664: 4663: 4659: 4615: 4614: 4610: 4553: 4552: 4545: 4504: 4503: 4499: 4462: 4461: 4457: 4433:. BCP 196. 4408: 4407: 4403: 4354: 4353: 4344: 4312: 4311: 4307: 4287:. BCP 153. 4258: 4257: 4253: 4208: 4207: 4196: 4188: 4181: 4177: 4176: 4172: 4163: 4161: 4153: 4152: 4148: 4139: 4137: 4127:Davis, Lidija. 4126: 4125: 4121: 4085:. BCP 153. 4056: 4055: 4040: 4031: 4029: 4021: 4020: 4016: 4007: 4005: 3999:"IPv6 – Google" 3997: 3996: 3992: 3983: 3981: 3973: 3972: 3968: 3911: 3906: 3896: 3894: 3887: 3882: 3881: 3864: 3860: 3847: 3843: 3838: 3821: 3793: 3751: 3750: 3737:fragment offset 3722: 3668: 3667: 3568:(8-byte blocks) 3566: 3565:Fragment offset 3559: 3552: 3545: 3538: 3493: 3486: 3485: 3466: 3465: 3417:(8-byte blocks) 3415: 3414:Fragment offset 3408: 3401: 3394: 3387: 3341: 3334: 3333: 3326:header checksum 3319:fragment offset 3292: 3260: 3254: 3148:Protocol Number 3134: 2657: 2656: 2643: 2642: 2625: 2624: 2593:Header checksum 2592: 2591: 2578: 2577: 2541: 2540: 2531:Fragment offset 2530: 2529: 2489: 2488: 2478: 2477: 2459: 2458: 2440: 2439: 2422:type of service 2413: 2412: 2398: 2397: 2384: 2383: 2359:(if IHL > 5) 2312:Header checksum 2283:Fragment offset 2069: 2049: 2037:IPv6 deployment 2014: 1961: 1955: 1929: 1926: 1925: 1918: 1915: 1914: 1896: 1868: 1862: 1851: 1848: 1847: 1826: 1824: 1810: 1808: 1783: 1782: 1775: 1772: 1769: 1768: 1761: 1758: 1757: 1744: 1743: 1736: 1735: 1728: 1727: 1720: 1719: 1712: 1711: 1705:192.168.255.255 1704: 1703: 1697:192.168.255.255 1696: 1695: 1688: 1687: 1680: 1677: 1674: 1673: 1666: 1663: 1662: 1641: 1639: 1625: 1623: 1598: 1597: 1590: 1589: 1582: 1581: 1574: 1571: 1568: 1567: 1557: 1554: 1553: 1537: 1531: 1516: 1513: 1510: 1509: 1502: 1501: 1497: 1491: 1455: 1422: 1420: 1400: 1397: 1395: 1381:Single Class A 1375: 1372: 1370: 1347: 1316: 1293: 1273: 1270: 1268: 1249: 1243:233.252.0.0/24 1225: 1222: 1220: 1201: 1195:203.0.113.0/24 1182: 1162: 1160: 1140: 1138: 1132:192.168.0.0/16 1107: 1101:192.88.99.0/24 1088: 1065: 1045: 1042: 1040: 1012: 1010: 1004:169.254.0.0/16 986: 983: 981: 955: 952: 950: 930: 927: 925: 905: 902: 900: 852: 838:(IANA) and the 825: 824: 776:network classes 764: 753: 752: 745: 744: 737: 736: 729: 728: 692: 691: 668: 651:(2) addresses. 647: 644: 641: 639: 620: 613: 578:internetworking 574: 551: 520:packet-switched 514:methods in the 512:internetworking 493: 313:Transport layer 93: 91: 88: 67:Internetworking 50: 28: 23: 22: 15: 12: 11: 5: 5852: 5850: 5842: 5841: 5836: 5831: 5826: 5821: 5816: 5811: 5806: 5796: 5795: 5792: 5791: 5786: 5768: 5755: 5747: 5746:External links 5744: 5741: 5740: 5726: 5706: 5617: 5606:ipwithease.com 5592: 5530: 5517:(4): 295–306. 5497: 5431: 5369: 5308: 5270: 5255: 5238: 5230:Informational. 5196: 5111: 5084: 5069: 5043: 5018: 4994: 4937: 4895: 4876: 4839: 4759: 4702: 4694:Informational. 4657: 4654:Informational. 4608: 4582:. BCP 51. 4543: 4531:Informational. 4497: 4489:Informational. 4455: 4401: 4393:Informational. 4342: 4305: 4251: 4194: 4170: 4146: 4119: 4038: 4014: 4003:www.google.com 3990: 3965: 3964: 3886: 3883: 3880: 3879: 3858: 3840: 3839: 3837: 3834: 3833: 3832: 3827: 3820: 3817: 3792: 3789: 3776: 3773: 3770: 3767: 3764: 3761: 3758: 3746:more fragments 3741: 3740: 3733: 3730:more fragments 3721: 3718: 3705: 3702: 3699: 3696: 3693: 3690: 3687: 3684: 3681: 3678: 3675: 3660:More Fragments 3651: 3650: 3647: 3644: 3641: 3638: 3635: 3631: 3630: 3627: 3624: 3621: 3618: 3615: 3611: 3610: 3607: 3604: 3601: 3598: 3595: 3591: 3590: 3587: 3584: 3581: 3578: 3575: 3571: 3570: 3563: 3561:More fragments 3556: 3549: 3542: 3535: 3514: 3511: 3506: 3502: 3499: 3496: 3473: 3460: 3459: 3456: 3453: 3450: 3447: 3444: 3440: 3439: 3436: 3433: 3430: 3427: 3424: 3420: 3419: 3412: 3410:More fragments 3405: 3398: 3391: 3384: 3362: 3359: 3354: 3350: 3347: 3344: 3330: 3329: 3322: 3315: 3312:more fragments 3308: 3291: 3288: 3273:Internet Layer 3256:Main article: 3253: 3250: 3247: 3246: 3243: 3238: 3234: 3233: 3230: 3225: 3221: 3220: 3217: 3212: 3208: 3207: 3204: 3199: 3195: 3194: 3191: 3186: 3182: 3181: 3178: 3173: 3169: 3168: 3165: 3160: 3156: 3155: 3152: 3149: 3133: 3130: 3129: 3128: 3125: 3124: 3121: 3118: 3114: 3113: 3110: 3107: 3103: 3102: 3099: 3096: 3092: 3091: 3088: 3085: 3081: 3080: 3077: 3074: 3070: 3069: 3066: 3063: 3059: 3058: 3055: 3052: 3048: 3047: 3044: 3041: 3037: 3036: 3033: 3030: 3026: 3025: 3022: 3019: 3015: 3014: 3011: 3008: 3004: 3003: 3000: 2997: 2993: 2992: 2989: 2986: 2982: 2981: 2978: 2975: 2971: 2970: 2967: 2964: 2960: 2959: 2956: 2953: 2949: 2948: 2945: 2942: 2938: 2937: 2934: 2931: 2927: 2926: 2923: 2920: 2916: 2915: 2912: 2909: 2905: 2904: 2901: 2898: 2894: 2893: 2890: 2887: 2883: 2882: 2879: 2876: 2872: 2871: 2868: 2865: 2861: 2860: 2857: 2854: 2850: 2849: 2846: 2843: 2839: 2838: 2835: 2832: 2828: 2827: 2824: 2821: 2817: 2816: 2813: 2810: 2806: 2805: 2802: 2799: 2795: 2794: 2791: 2788: 2780: 2779: 2771: 2770: 2767: 2766: 2763: 2760: 2756: 2755: 2752: 2749: 2745: 2744: 2741: 2738: 2734: 2733: 2722: 2719: 2715: 2714: 2711: 2708: 2704: 2703: 2700: 2697: 2689: 2688: 2685: 2673: 2661: 2654: 2647: 2640: 2629: 2626:Source address 2622: 2615: 2612: 2596: 2589: 2582: 2575: 2568: 2545: 2538: 2534: 2527: 2523: 2507: 2506: 2505: 2502: 2499: 2493: 2486: 2482: 2479:Identification 2475: 2463: 2456: 2445: 2433: 2418: 2406: 2402: 2395: 2388: 2378: 2377: 2374: 2370: 2369: 2366: 2362: 2361: 2353: 2350: 2346: 2345: 2338: 2335: 2331: 2330: 2327:Source address 2323: 2320: 2316: 2315: 2308: 2301: 2294: 2291: 2287: 2286: 2279: 2272: 2269:Identification 2265: 2262: 2258: 2257: 2250: 2243: 2236: 2229: 2222: 2219: 2215: 2214: 2211: 2208: 2205: 2202: 2199: 2196: 2193: 2190: 2187: 2184: 2181: 2178: 2175: 2172: 2169: 2166: 2163: 2160: 2157: 2154: 2151: 2148: 2145: 2142: 2139: 2136: 2133: 2130: 2127: 2124: 2121: 2118: 2113: 2109: 2108: 2105: 2102: 2099: 2096: 2091: 2068: 2065: 2048: 2045: 2009: 2008: 1998: 1992: 1957:Main article: 1954: 1951: 1900:point-to-point 1895: 1892: 1864:Main article: 1861: 1858: 1841: 1840: 1834: 1833: 1830: 1822: 1818: 1817: 1814: 1806: 1805:Network space 1802: 1801: 1798: 1795: 1656: 1655: 1649: 1648: 1647:192.168.5.255 1645: 1637: 1633: 1632: 1629: 1621: 1620:Network space 1617: 1616: 1613: 1610: 1530: 1527: 1493:Main article: 1490: 1487: 1454: 1451: 1434: 1433: 1430: 1429: 1426: 1418: 1415: 1414:192.168.0.0/16 1412: 1408: 1407: 1404: 1393: 1390: 1387: 1383: 1382: 1379: 1368: 1365: 1362: 1358: 1357: 1349: 1344: 1341: 1335: 1315: 1312: 1311: 1310: 1307: 1306: 1299: 1296: 1291: 1288: 1284: 1283: 1280: 1277: 1266: 1263: 1259: 1258: 1255: 1254:Documentation 1252: 1247: 1244: 1240: 1239: 1232: 1229: 1218: 1215: 1211: 1210: 1207: 1206:Documentation 1204: 1199: 1196: 1192: 1191: 1188: 1187:Documentation 1185: 1180: 1177: 1173: 1172: 1169: 1166: 1158: 1155: 1154:198.18.0.0/15 1151: 1150: 1147: 1144: 1136: 1133: 1129: 1128: 1123:address block 1113: 1110: 1105: 1102: 1098: 1097: 1094: 1093:Documentation 1091: 1086: 1083: 1079: 1078: 1071: 1068: 1063: 1060: 1056: 1055: 1052: 1049: 1038: 1035: 1034:172.16.0.0/12 1031: 1030: 1019: 1016: 1008: 1005: 1001: 1000: 993: 990: 979: 976: 972: 971: 962: 959: 948: 945: 944:100.64.0.0/10 941: 940: 937: 934: 923: 920: 916: 915: 912: 909: 898: 895: 891: 890: 887: 884: 881: 880:Address range 878: 877:Address block 851: 848: 763: 760: 667: 664: 612: 609: 593:connectionless 582:internet layer 573: 570: 550: 547: 495: 494: 492: 491: 484: 477: 469: 466: 465: 464: 463: 456: 451: 446: 441: 433: 432: 426: 425: 424: 423: 416: 411: 406: 401: 396: 386: 385: 384: 379: 366: 365: 363:Internet layer 359: 358: 357: 356: 349: 344: 339: 334: 329: 324: 316: 315: 309: 308: 307: 306: 299: 294: 289: 284: 279: 274: 269: 264: 259: 254: 249: 244: 239: 234: 229: 224: 219: 214: 209: 204: 199: 194: 189: 179: 174: 169: 159: 151: 150: 144: 143: 133: 132: 127: 121: 120: 115: 109: 108: 103: 99: 98: 85: 81: 80: 75: 71: 70: 64: 60: 59: 56: 52: 51: 48: 40: 39: 37:Protocol stack 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 5851: 5840: 5837: 5835: 5832: 5830: 5827: 5825: 5822: 5820: 5817: 5815: 5812: 5810: 5807: 5805: 5802: 5801: 5799: 5790: 5787: 5782: 5777: 5773: 5769: 5766: 5762: 5759: 5756: 5753: 5750: 5749: 5745: 5736: 5730: 5727: 5716: 5710: 5707: 5703: 5699: 5695: 5691: 5687: 5683: 5679: 5675: 5671: 5667: 5663: 5659: 5655: 5650: 5647: 5642: 5637: 5633: 5632: 5627: 5621: 5618: 5607: 5603: 5596: 5593: 5589: 5585: 5581: 5577: 5572: 5569: 5565: 5561: 5556: 5551: 5547: 5543: 5542: 5534: 5531: 5525: 5520: 5516: 5512: 5508: 5501: 5498: 5494: 5490: 5486: 5482: 5478: 5474: 5470: 5466: 5461: 5458: 5453: 5448: 5444: 5443: 5435: 5432: 5428: 5424: 5420: 5416: 5412: 5408: 5403: 5400: 5395: 5390: 5386: 5385: 5380: 5373: 5370: 5366: 5362: 5358: 5354: 5350: 5345: 5342: 5339:. STD 5. 5337: 5332: 5328: 5324: 5323: 5318: 5312: 5309: 5304: 5301: 5296: 5291: 5287: 5286: 5281: 5274: 5271: 5266: 5262: 5258: 5256:9781509007066 5252: 5248: 5242: 5239: 5235: 5231: 5226: 5223: 5218: 5213: 5209: 5208: 5200: 5197: 5193: 5189: 5185: 5181: 5177: 5173: 5169: 5165: 5161: 5157: 5153: 5149: 5144: 5141: 5136: 5131: 5127: 5126: 5121: 5115: 5112: 5099: 5095: 5088: 5085: 5080: 5073: 5070: 5058: 5054: 5047: 5044: 5033:on 2011-01-25 5032: 5028: 5022: 5019: 5008: 5004: 4998: 4995: 4991: 4987: 4983: 4979: 4975: 4970: 4967: 4962: 4957: 4953: 4952: 4947: 4941: 4938: 4934: 4930: 4925: 4922: 4917: 4912: 4908: 4907: 4899: 4896: 4891: 4887: 4880: 4877: 4874: 4869: 4866: 4861: 4856: 4852: 4851: 4843: 4840: 4836: 4832: 4828: 4824: 4820: 4816: 4812: 4808: 4804: 4800: 4795: 4792: 4789:. STD 3. 4787: 4782: 4778: 4777: 4772: 4766: 4764: 4760: 4757: 4752: 4748: 4744: 4739: 4736: 4731: 4726: 4722: 4721: 4716: 4712: 4706: 4703: 4699: 4695: 4690: 4687: 4682: 4677: 4673: 4672: 4667: 4661: 4658: 4655: 4650: 4647: 4643: 4639: 4634: 4629: 4625: 4621: 4620: 4612: 4609: 4605: 4601: 4597: 4593: 4588: 4585: 4581: 4577: 4572: 4567: 4563: 4559: 4558: 4550: 4548: 4544: 4540: 4537:and RFC 4536: 4532: 4527: 4524: 4519: 4514: 4510: 4509: 4501: 4498: 4494: 4490: 4485: 4482: 4477: 4472: 4468: 4467: 4459: 4456: 4452: 4448: 4444: 4439: 4436: 4431: 4426: 4422: 4418: 4417: 4412: 4405: 4402: 4398: 4394: 4389: 4386: 4382: 4378: 4373: 4368: 4364: 4360: 4359: 4351: 4349: 4347: 4343: 4340: 4335: 4332: 4327: 4322: 4318: 4317: 4309: 4306: 4302: 4298: 4293: 4290: 4286: 4282: 4277: 4272: 4268: 4264: 4263: 4255: 4252: 4248: 4244: 4240: 4236: 4231: 4228: 4225:. BCP 5. 4223: 4218: 4214: 4213: 4205: 4203: 4201: 4199: 4195: 4187: 4180: 4174: 4171: 4160: 4156: 4150: 4147: 4136: 4135: 4130: 4123: 4120: 4116: 4112: 4108: 4104: 4100: 4096: 4091: 4088: 4084: 4080: 4075: 4070: 4066: 4062: 4061: 4053: 4051: 4049: 4047: 4045: 4043: 4039: 4028: 4024: 4018: 4015: 4004: 4000: 3994: 3991: 3980: 3976: 3970: 3967: 3963: 3959: 3955: 3951: 3947: 3943: 3939: 3935: 3931: 3926: 3921: 3917: 3910: 3904: 3899: 3892: 3884: 3876: 3872: 3868: 3862: 3859: 3855: 3851: 3845: 3842: 3835: 3831: 3828: 3826: 3823: 3822: 3818: 3816: 3814: 3810: 3806: 3802: 3798: 3790: 3788: 3774: 3771: 3768: 3765: 3762: 3759: 3756: 3747: 3738: 3734: 3731: 3727: 3726: 3725: 3719: 3717: 3703: 3700: 3697: 3694: 3691: 3688: 3685: 3682: 3679: 3676: 3673: 3664: 3661: 3656: 3648: 3645: 3642: 3639: 3636: 3633: 3632: 3628: 3625: 3622: 3619: 3616: 3613: 3612: 3608: 3605: 3602: 3599: 3596: 3593: 3592: 3588: 3585: 3582: 3579: 3576: 3573: 3572: 3564: 3562: 3557: 3550: 3543: 3536: 3533: 3532: 3529: 3526: 3512: 3509: 3504: 3500: 3497: 3494: 3471: 3457: 3454: 3451: 3448: 3445: 3442: 3441: 3437: 3434: 3431: 3428: 3425: 3422: 3421: 3413: 3411: 3406: 3399: 3392: 3385: 3382: 3381: 3378: 3374: 3360: 3357: 3352: 3348: 3345: 3342: 3327: 3323: 3320: 3316: 3313: 3309: 3306: 3302: 3301: 3300: 3296: 3290:Fragmentation 3289: 3287: 3285: 3281: 3278:In contrast, 3276: 3274: 3270: 3266: 3259: 3251: 3244: 3242: 3239: 3236: 3235: 3231: 3229: 3226: 3223: 3222: 3218: 3216: 3213: 3210: 3209: 3205: 3203: 3200: 3197: 3196: 3192: 3190: 3187: 3184: 3183: 3179: 3177: 3174: 3171: 3170: 3166: 3164: 3161: 3158: 3157: 3154:Abbreviation 3153: 3151:Protocol Name 3150: 3147: 3146: 3143: 3141: 3137: 3131: 3122: 3119: 3116: 3115: 3111: 3108: 3105: 3104: 3100: 3097: 3094: 3093: 3089: 3086: 3083: 3082: 3078: 3075: 3072: 3071: 3067: 3064: 3061: 3060: 3057:Router Alert 3056: 3053: 3050: 3049: 3045: 3042: 3039: 3038: 3034: 3031: 3028: 3027: 3023: 3020: 3017: 3016: 3012: 3009: 3006: 3005: 3001: 2998: 2995: 2994: 2990: 2987: 2984: 2983: 2979: 2976: 2973: 2972: 2968: 2965: 2962: 2961: 2957: 2954: 2951: 2950: 2946: 2943: 2940: 2939: 2935: 2932: 2929: 2928: 2924: 2921: 2918: 2917: 2913: 2910: 2907: 2906: 2902: 2899: 2896: 2895: 2891: 2888: 2885: 2884: 2880: 2877: 2874: 2873: 2869: 2866: 2863: 2862: 2858: 2855: 2852: 2851: 2847: 2844: 2841: 2840: 2837:Record Route 2836: 2833: 2830: 2829: 2825: 2822: 2819: 2818: 2815:No Operation 2814: 2811: 2808: 2807: 2803: 2800: 2797: 2796: 2792: 2789: 2786: 2785: 2782: 2781: 2777: 2773: 2772: 2764: 2761: 2758: 2757: 2753: 2750: 2748:Option Length 2747: 2746: 2742: 2739: 2737:Option Number 2736: 2735: 2731: 2727: 2723: 2720: 2717: 2716: 2712: 2709: 2706: 2705: 2701: 2698: 2695: 2694: 2691: 2690: 2686: 2683: 2679: 2674: 2670: 2666: 2665:options field 2662: 2655: 2652: 2648: 2641: 2638: 2634: 2630: 2623: 2620: 2616: 2613: 2610: 2606: 2601: 2597: 2590: 2587: 2583: 2576: 2573: 2569: 2566: 2562: 2558: 2554: 2550: 2547:An eight-bit 2546: 2539: 2535: 2528: 2524: 2521: 2517: 2513: 2508: 2503: 2500: 2497: 2496: 2494: 2487: 2483: 2476: 2473: 2468: 2464: 2457: 2454: 2450: 2446: 2437: 2434: 2431: 2430:Voice over IP 2427: 2423: 2419: 2410: 2407: 2403: 2396: 2393: 2389: 2382: 2381: 2375: 2372: 2371: 2367: 2364: 2363: 2360: 2358: 2351: 2348: 2347: 2344: 2343: 2336: 2333: 2332: 2329: 2328: 2321: 2318: 2317: 2314: 2313: 2307: 2306: 2300: 2299: 2292: 2289: 2288: 2285: 2284: 2278: 2277: 2271: 2270: 2263: 2260: 2259: 2256: 2255: 2249: 2248: 2242: 2241: 2235: 2234: 2228: 2227: 2220: 2217: 2216: 2212: 2209: 2206: 2203: 2200: 2197: 2194: 2191: 2188: 2185: 2182: 2179: 2176: 2173: 2170: 2167: 2164: 2161: 2158: 2155: 2152: 2149: 2146: 2143: 2140: 2137: 2134: 2131: 2128: 2125: 2122: 2119: 2117: 2114: 2111: 2110: 2095: 2092: 2090: 2087: 2086: 2080: 2078: 2074: 2066: 2064: 2062: 2058: 2054: 2046: 2044: 2042: 2038: 2034: 2030: 2025: 2022: 2018: 2012: 2006: 2002: 1999: 1996: 1993: 1990: 1987: 1986: 1985: 1983: 1979: 1975: 1965: 1960: 1952: 1950: 1947: 1945: 1941: 1937: 1933: 1922: 1911: 1908: 1903: 1901: 1898:A unnumbered 1893: 1891: 1889: 1885: 1880: 1878: 1873: 1870:Hosts on the 1867: 1859: 1857: 1855: 1835: 1832:203.0.113.31 1831: 1823: 1820: 1819: 1816:203.0.113.16 1815: 1807: 1804: 1803: 1799: 1796: 1793: 1792: 1789: 1787: 1779: 1765: 1753: 1750: 1748: 1740: 1732: 1725:, etc. Also, 1724: 1721:192.168.2.255 1716: 1713:192.168.1.255 1708: 1700: 1692: 1684: 1670: 1650: 1646: 1638: 1635: 1634: 1630: 1622: 1619: 1618: 1614: 1611: 1608: 1607: 1604: 1602: 1599:192.168.5.255 1594: 1586: 1583:255.255.255.0 1579:(subnet mask 1578: 1563: 1561: 1550: 1546: 1542: 1536: 1528: 1526: 1524: 1520: 1506: 1496: 1488: 1486: 1484: 1480: 1476: 1472: 1468: 1463: 1461: 1452: 1450: 1447: 1443: 1439: 1427: 1416: 1413: 1410: 1409: 1405: 1391: 1389:172.16.0.0/12 1388: 1385: 1384: 1380: 1366: 1363: 1360: 1359: 1355: 1354: 1350: 1345: 1343:Address range 1342: 1339: 1336: 1333: 1332: 1326: 1325: 1324: 1322: 1313: 1304: 1300: 1297: 1289: 1286: 1285: 1281: 1278: 1264: 1261: 1260: 1256: 1253: 1245: 1242: 1241: 1237: 1233: 1230: 1216: 1213: 1212: 1208: 1205: 1197: 1194: 1193: 1189: 1186: 1178: 1175: 1174: 1170: 1167: 1156: 1153: 1152: 1148: 1145: 1134: 1131: 1130: 1126: 1122: 1118: 1114: 1111: 1103: 1100: 1099: 1095: 1092: 1084: 1082:192.0.2.0/24 1081: 1080: 1076: 1072: 1069: 1061: 1059:192.0.0.0/24 1058: 1057: 1053: 1050: 1036: 1033: 1032: 1028: 1024: 1020: 1017: 1006: 1003: 1002: 998: 994: 991: 977: 974: 973: 970: 966: 963: 960: 946: 943: 942: 938: 935: 921: 918: 917: 913: 910: 896: 893: 892: 888: 885: 882: 879: 876: 875: 869: 868: 867: 865: 861: 857: 849: 847: 845: 841: 837: 833: 829: 821: 817: 813: 809: 805: 801: 797: 793: 788: 786: 781: 777: 772: 770: 761: 759: 757: 754:127.0.255.250 749: 741: 733: 725: 721: 716: 714: 710: 709:CIDR notation 706: 704: 700: 696: 687: 685: 681: 677: 673: 665: 663: 661: 657: 652: 637: 636:address space 629: 624: 618: 610: 608: 606: 602: 598: 594: 589: 587: 583: 579: 571: 569: 567: 563: 559: 554: 548: 546: 544: 539: 537: 533: 529: 525: 521: 517: 513: 509: 505: 501: 490: 485: 483: 478: 476: 471: 470: 468: 467: 462: 461: 457: 455: 452: 450: 447: 445: 442: 440: 437: 436: 435: 434: 431: 427: 422: 421: 417: 415: 412: 410: 407: 405: 402: 400: 397: 394: 390: 387: 383: 380: 378: 375: 374: 373: 370: 369: 368: 367: 364: 360: 355: 354: 350: 348: 345: 343: 340: 338: 335: 333: 330: 328: 325: 323: 320: 319: 318: 317: 314: 310: 305: 304: 300: 298: 295: 293: 290: 288: 285: 283: 280: 278: 275: 273: 270: 268: 265: 263: 260: 258: 255: 253: 250: 248: 245: 243: 240: 238: 235: 233: 230: 228: 225: 223: 220: 218: 215: 213: 210: 208: 205: 203: 200: 198: 195: 193: 190: 187: 183: 180: 178: 175: 173: 170: 167: 163: 160: 158: 155: 154: 153: 152: 149: 145: 142: 138: 131: 128: 126: 122: 119: 118:Network layer 116: 114: 110: 107: 104: 100: 86: 82: 79: 76: 72: 68: 65: 61: 57: 53: 46: 41: 38: 34: 19: 18:IPv4 Internet 5771: 5729: 5718:. Retrieved 5709: 5653: 5630: 5620: 5609:. Retrieved 5605: 5595: 5575: 5540: 5533: 5514: 5510: 5500: 5464: 5441: 5434: 5406: 5383: 5372: 5348: 5321: 5311: 5284: 5273: 5246: 5241: 5229: 5206: 5199: 5147: 5124: 5114: 5102:. Retrieved 5098:the original 5087: 5072: 5060:. Retrieved 5046: 5035:. Retrieved 5031:the original 5021: 5010:. Retrieved 5006: 4997: 4973: 4950: 4940: 4928: 4905: 4898: 4889: 4879: 4872: 4849: 4842: 4798: 4775: 4754: 4742: 4719: 4705: 4693: 4670: 4660: 4653: 4618: 4611: 4591: 4556: 4530: 4507: 4500: 4488: 4465: 4458: 4442: 4415: 4411:B. Carpenter 4404: 4392: 4357: 4338: 4315: 4308: 4296: 4261: 4254: 4234: 4211: 4186:the original 4173: 4162:. Retrieved 4158: 4149: 4138:. Retrieved 4132: 4122: 4094: 4059: 4030:. Retrieved 4027:www.iana.org 4026: 4017: 4006:. Retrieved 4002: 3993: 3982:. 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Reynolds 4666:J. Reynolds 3979:BGP Reports 3875:MAC address 3813:reverse ARP 3544:Header size 3393:Header size 2925:Traceroute 2914:Time Stamp 2790:Option Name 2776:Option Type 2759:Option Data 2699:Size (bits) 2598:The 16-bit 1797:Binary form 1745:192.168.2.0 1737:192.168.1.0 1729:192.168.0.0 1689:192.168.0.0 1681:255.255.0.0 1675:192.168.0.0 1612:Binary form 1591:192.168.5.0 1569:192.168.5.0 1234:In use for 919:10.0.0.0/8 814:introduced 703:hexadecimal 601:upper layer 49:IPv4 packet 5798:Categories 5720:2012-05-10 5611:2022-11-21 5120:S. Deering 5062:3 February 5037:2011-01-23 5012:2021-11-25 4164:2020-08-19 4140:2024-05-10 4032:2022-01-28 4008:2022-01-28 3984:2013-01-09 3958:Q104661268 3942:9708517136 3905:) : 3885:References 3735:The field 3720:Reassembly 2991:Stream ID 2870:MTU Reply 2859:MTU Probe 2572:traceroute 2520:traceroute 2472:fragmented 2057:link layer 1888:namespaces 1533:See also: 1364:10.0.0.0/8 894:0.0.0.0/8 769:rest field 762:Allocation 617:IP address 611:Addressing 591:IPv4 is a 518:and other 430:Link layer 102:Influenced 5654:Obsolete. 5626:J. Postel 5564:2070-1721 5317:J. Postel 5265:972636788 5148:Obsolete. 4929:Obsolete. 4771:R. Braden 4756:network". 4743:Obsolete. 4715:J. 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Baker 3954:Wikidata 3871:Ethernet 3867:IEEE 802 3854:Evil bit 3819:See also 3807:(DHCP), 3269:fragment 3117:222/0xDE 3106:205/0xCD 3095:158/0x9E 3084:152/0x98 3073:151/0x97 3062:149/0x95 3051:148/0x94 3040:147/0x93 3029:145/0x91 3018:144/0x90 3007:142/0x8E 2996:137/0x89 2985:136/0x88 2974:134/0x86 2963:133/0x85 2952:131/0x83 2941:130/0x82 2762:Variable 2579:Protocol 2451:without 2368:⋮ 2365:⋮ 2305:Protocol 1940:loopback 1872:Internet 1642:11111111 1626:00000000 1523:loopback 1489:Loopback 1460:Zeroconf 1444:, which 1353:Classful 832:classful 780:classful 726:address 724:loopback 516:Internet 69:protocol 4413:(ed.). 3554:(bytes) 3547:(bytes) 3540:(bytes) 3403:(bytes) 3396:(bytes) 3389:(bytes) 2930:94/0x5E 2919:82/0x52 2908:68/0x44 2897:30/0x1E 2886:25/0x19 2881:ENCODE 2875:15/0x0F 2864:12/0x0C 2853:11/0x0B 2842:10/0x0A 2726:control 2658:Options 2526:packet. 2385:Version 2357:Options 2226:Version 1671:subnet 1298:Subnet 1075:DS-Lite 1029:server 1018:Subnet 699:decimal 684:periods 680:decimal 607:(TCP). 586:routing 580:at the 572:Purpose 549:History 528:ARPANET 460:more... 444:Tunnels 420:more... 353:more... 303:more... 292:TLS/SSL 247:ONC/RPC 184: ( 92: ( 63:Purpose 5778: 5754:(IANA) 5562: 5263: 5253: 4640: 4578: 4379: 4283: 4081: 3956: 3948: 3940: 3932: 3848:As an 3623:1,480 3617:1,500 3603:1,000 3597:1,020 3583:1,480 3577:1,500 3452:2,020 3446:2,040 3432:2,480 3426:2,500 3219:ENCAP 3054:RTRALT 3043:ADDEXT 2878:ENCODE 2831:7/0x07 2820:2/0x02 2809:1/0x01 2798:0/0x00 2707:Copied 2680: 2639:(NAT). 2561:router 2467:16-bit 2392:packet 2112:Octet 2089:Offset 2067:Header 2053:packet 2051:An IP 1077:(/29) 886:Scope 810: 802: 794: 676:octets 628:binary 543:32-bit 524:SATNET 287:Telnet 186:HTTP/3 125:RFC(s) 5007:Cisco 4189:(PDF) 4182:(PDF) 3946:S2CID 3912:(PDF) 3836:Notes 3775:4,500 3704:4,500 3692:3,960 3501:2,480 3343:1,500 3245:SCTP 3232:OSPF 3180:IGMP 3167:ICMP 3021:IMITD 2977:CIPSO 2966:E-SEC 2696:Field 2490:Flags 2465:This 2276:Flags 2094:Octet 2033:6bone 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