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Name Service Switch

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Sun engineers' original design of the configuration file and runtime loading of name service back-end libraries has withstood the test of time as operating systems have evolved and new name services are introduced. Over the years, programmers ported the NSS configuration file with nearly identical
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The order of the source databases determines the order the NSS will attempt to look up those sources to resolve queries for the specified service. A bracketed list of criteria may be specified following each source name to govern the conditions under which the NSS will proceed to querying the next
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passwd: files ldap shadow: files group: files ldap hosts: dns nis files ethers: files nis netmasks: files nis networks: files nis protocols: files nis rpc: files nis services: files nis automount: files aliases: files
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were the first to design and implement the Name Service Switch. They fulfilled Solaris requirements with the nsswitch.conf file specification and the implementation choice to load database access modules as
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The nsswitch.conf file has line entries for each service consisting of a database name in the first field, terminated by a colon, and a list of possible source databases in the second field.
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that connects a computer with a variety of sources of common configuration databases and name resolution mechanisms. These sources include local operating system files (such as
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systems either accessed only local files or had hard-coded rules for accessing files or network-stored databases.
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was a notable exception with its nearly identical functionality of the NSS configuration file in
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usually configures the operating system's name services using the file
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implementations to many other operating systems including
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Solaris' compliance with SVR4, which Sun Microsystems and
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Name Service Switch implementation in the GNU C Library
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Unix System Laboratories jointly developed by merging
338:. More than two decades after the NSS was invented, 148: 103: 115: 109: 217:source based on the preceding source's response. 43:but its sources remain unclear because it lacks 310:, which Sun was also the first to introduce. 8: 290:directory service in Solaris to supersede 387:"Name Service Switch (The GNU C Library)" 74:Learn how and when to remove this message 378: 169:Lightweight Directory Access Protocol 147:. This file lists databases (such as 7: 436:Another NSS module supporting LDAP 342:implements it almost identically. 243:first developed the NSS for their 14: 367:Pluggable Authentication Modules 209:A typical file might look like: 20: 1: 201:Windows Internet Name Service 308:dynamically loaded libraries 177:Network Information Service 125:Network Information Service 484: 86:Operating system mechanism 442:NSS module supporting AFS 29:This article includes a 58:more precise citations. 97:) is an interface of 141:system administrator 270:of their choosing ( 91:Name Service Switch 468:Directory services 463:Domain Name System 352:BSD Authentication 247:operating system. 193:Domain Name System 163:for local files, 145:/etc/nsswitch.conf 121:Domain Name System 31:list of references 127:(NIS, NIS+), and 84: 83: 76: 475: 419: 418: 416:nsswitch.conf(5) 401: 400: 398: 397: 383: 357:Group (database) 241:Sun Microsystems 236: 146: 118: 112: 106: 79: 72: 68: 65: 59: 54:this article by 45:inline citations 24: 23: 16: 483: 482: 478: 477: 476: 474: 473: 472: 448: 447: 414: 413: 410: 405: 404: 395: 393: 385: 384: 380: 375: 348: 268:transport layer 234: 223: 214: 144: 137: 114: 108: 102: 87: 80: 69: 63: 60: 49: 35:related reading 25: 21: 12: 11: 5: 481: 479: 471: 470: 465: 460: 450: 449: 446: 445: 439: 433: 428: 409: 408:External links 406: 403: 402: 377: 376: 374: 371: 370: 369: 364: 359: 354: 347: 344: 297:Sun engineers 222: 219: 211: 136: 133: 85: 82: 81: 39:external links 28: 26: 19: 13: 10: 9: 6: 4: 3: 2: 480: 469: 466: 464: 461: 459: 456: 455: 453: 443: 440: 437: 434: 432: 429: 427: 424:File Formats 423: 417: 412: 411: 407: 392: 388: 382: 379: 372: 368: 365: 363: 360: 358: 355: 353: 350: 349: 345: 343: 341: 337: 333: 329: 325: 321: 317: 311: 309: 304: 300: 299:Thomas Maslen 295: 293: 289: 285: 281: 277: 273: 269: 265: 261: 257: 256:UNIX System V 253: 248: 246: 242: 238: 235:/etc/svc.conf 232: 228: 220: 218: 210: 207: 204: 202: 198: 194: 190: 186: 182: 178: 174: 170: 166: 162: 158: 154: 150: 142: 135:nsswitch.conf 134: 132: 130: 126: 122: 117: 111: 105: 100: 96: 92: 78: 75: 67: 57: 53: 47: 46: 40: 36: 32: 27: 18: 17: 394:. Retrieved 390: 381: 312: 296: 283: 249: 239: 224: 215: 208: 205: 196: 188: 180: 172: 164: 160: 138: 94: 90: 88: 70: 64:October 2022 61: 50:Please help 42: 438:: nss-ldapd 391:www.gnu.org 362:Name server 303:Sanjay Dani 195:(DNS), and 123:(DNS), the 104:/etc/passwd 56:introducing 452:Categories 396:2024-03-13 373:References 116:/etc/hosts 110:/etc/group 444:: nss_afs 227:Unix-like 346:See also 340:GNU libc 252:AT&T 225:Earlier 191:for the 175:for the 167:for the 316:FreeBSD 245:Solaris 221:History 181:nisplus 119:), the 52:improve 426:Manual 422:NetBSD 320:NetBSD 284:TI-RPC 231:Ultrix 153:shadow 149:passwd 113:, and 328:HP-UX 324:Linux 264:Xenix 161:files 157:group 99:glibc 37:, or 458:Unix 334:and 332:IRIX 301:and 288:NIS+ 262:and 199:for 197:wins 185:NIS+ 183:for 165:ldap 155:and 129:LDAP 89:The 336:AIX 292:NIS 280:RPC 274:or 272:OSI 260:BSD 189:dns 173:nis 95:NSS 454:: 389:. 330:, 326:, 322:, 318:, 276:IP 258:, 237:. 203:. 187:, 179:, 171:, 151:, 139:A 131:. 107:, 41:, 33:, 399:. 282:( 93:( 77:) 71:( 66:) 62:( 48:.

Index

list of references
related reading
external links
inline citations
improve
introducing
Learn how and when to remove this message
glibc
/etc/passwd
/etc/group
/etc/hosts
Domain Name System
Network Information Service
LDAP
system administrator
passwd
shadow
group
Lightweight Directory Access Protocol
Network Information Service
NIS+
Domain Name System
Windows Internet Name Service
Unix-like
Ultrix
Sun Microsystems
Solaris
AT&T
UNIX System V
BSD

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