doc/overview.texi

   1 @node Overview, Installation, Top, Top
   2 @comment  node-name,  next,  previous,  up
   3 @chapter Overview
   4 @cindex Overview
   5
   6   Zebra is a routing software package that provides TCP/IP based
   7 routing services with routing protocols support such as RIPv1, RIPv2,
   8 RIPng, OSPFv2, OSPFv3, BGP-4, and BGP-4+ (@pxref{Supported RFC}).
   9 Zebra also supports special BGP Route Reflector and Route Server
  10 behavior.  In addition to traditional IPv4 routing protocols, Zebra
  11 also supports IPv6 routing protocols.  With SNMP daemon which supports
  12 SMUX protocol, Zebra provides routing protocol MIBs (@pxref{SNMP
  13 Support}).
  14
  15   Zebra uses an advanced software architecture to provide you with a
  16 high quality, multi server routing engine.  Zebra has an interactive
  17 user interface for each routing protocol and supports common client
  18 commands.  Due to this design, you can add new protocol daemons to Zebra
  19 easily.  You can use Zebra library as your program's client user
  20 interface.
  21
  22   Zebra is an official @sc{gnu} software and distributed under the
  23 @sc{gnu} General Public License.
  24
  25 @menu
  26 * About Zebra::                 Basic information about Zebra
  27 * System Architecture::         The Zebra system architecture
  28 * Supported Platforms::         Supported platforms and future plans
  29 * Supported RFC::               Supported RFCs
  30 * How to get Zebra::
  31 * Mailing List::                Mailing list information
  32 * Bug Reports::                 Mail address for bug data
  33 @end menu
  34
  35 @node About Zebra, System Architecture, Overview, Overview
  36 @comment  node-name,  next,  previous,  up
  37 @section About Zebra
  38 @cindex About Zebra
  39
  40   Today, TCP/IP networks are covering all of the world.  The Internet
  41 has been deployed in many countries, companies, and to the home.  When
  42 you connect to the Internet your packet will pass many routers which
  43 have TCP/IP routing functionality.
  44
  45   A system with Zebra installed acts as a dedicated router.  With Zebra,
  46 your machine exchanges routing information with other routers using
  47 routing protocols.  Zebra uses this information to update the kernel
  48 routing table so that the right data goes to the right place.  You can
  49 dynamically change the configuration and you may view routing table
  50 information from the Zebra terminal interface.
  51
  52   Adding to routing protocol support, Zebra can setup interface's flags,
  53 interface's address, static routes and so on.  If you have a small
  54 network, or a stub network, or xDSL connection, configuring the Zebra
  55 routing software is very easy.  The only thing you have to do is to set
  56 up the interfaces and put a few commands about static routes and/or
  57 default routes.  If the network is rather large, or if the network
  58 structure changes frequently, you will want to take advantage of Zebra's
  59 dynamic routing protocol support for protocols such as RIP, OSPF or BGP.
  60 Zebra is with you.
  61
  62   Traditionally, UNIX based router configuration is done by
  63 @command{ifconfig} and @command{route} commands.  Status of routing
  64 table is displayed by @command{netstat} utility.  Almost of these
  65 commands work only if the user has root privileges.  Zebra has a different
  66 system administration method.  There are two user modes in Zebra.  One is
  67 normal mode, the other is enable mode.  Normal mode user can only view
  68 system status, enable mode user can change system configuration.  This
  69 UNIX account independent feature will be great help to the router
  70 administrator.
  71
  72   Currently, Zebra supports common unicast routing protocols.  Multicast
  73 routing protocols such as BGMP, PIM-SM, PIM-DM will be supported in
  74 Zebra 2.0.  MPLS support is going on.  In the future, TCP/IP filtering
  75 control, QoS control, diffserv configuration will be added to Zebra.
  76 Zebra project's final goal is making a productive, quality free TCP/IP
  77 routing software.
  78
  79 @node System Architecture, Supported Platforms, About Zebra, Overview
  80 @comment  node-name,  next,  previous,  up
  81 @section System Architecture
  82 @cindex System architecture
  83 @cindex Software architecture
  84 @cindex Software internals
  85
  86   Traditional routing software is made as a one process program which
  87 provides all of the routing protocol functionalities.  Zebra takes a
  88 different approach.  It is made from a collection of several daemons
  89 that work together to build the routing table.  There may be several
  90 protocol-specific routing daemons and zebra the kernel routing manager.
  91
  92   The @command{ripd} daemon handles the RIP protocol, while
  93 @command{ospfd} is a daemon which supports OSPF version 2.
  94 @command{bgpd} supports the BGP-4 protocol.  For changing the kernel
  95 routing table and for redistribution of routes between different routing
  96 protocols, there is a kernel routing table manager @command{zebra}
  97 daemon.  It is easy to add a new routing protocol daemons to the entire
  98 routing system without affecting any other software.  You need to run only
  99 the protocol daemon associated with routing protocols in use.  Thus,
 100 user may run a specific daemon and send routing reports to a central
 101 routing console.
 102
 103   There is no need for these daemons to be running on the same machine.
 104 You can even run several same protocol daemons on the same machine.  This
 105 architecture creates new possibilities for the routing system.
 106
 107 @example
 108 @group
 109 +----+  +----+  +-----+  +-----+
 110 |bgpd|  |ripd|  |ospfd|  |zebra|
 111 +----+  +----+  +-----+  +-----+
 112                             |
 113 +---------------------------|--+
 114 |                           v  |
 115 |  UNIX Kernel  routing table  |
 116 |                              |
 117 +------------------------------+
 118
 119     Zebra System Architecture
 120 @end group
 121 @end example
 122
 123   Multi-process architecture brings extensibility, modularity and
 124 maintainability.  At the same time it also brings many configuration
 125 files and terminal interfaces.  Each daemon has it's own configuration
 126 file and terminal interface.  When you configure a static route, it must
 127 be done in @command{zebra} configuration file.  When you configure BGP
 128 network it must be done in @command{bgpd} configuration file.  This can be a
 129 very annoying thing.  To resolve the problem, Zebra provides integrated
 130 user interface shell called @command{vtysh}.  @command{vtysh} connects to
 131 each daemon with UNIX domain socket and then works as a proxy for user input.
 132
 133   Zebra was planned to use multi-threaded mechanism when it runs with a
 134 kernel that supports multi-threads.  But at the moment, the thread
 135 library which comes with @sc{gnu}/Linux or FreeBSD has some problems with
 136 running reliable services such as routing software, so we don't use
 137 threads at all.  Instead we use the @command{select(2)} system call for
 138 multiplexing the events.
 139
 140   When @command{zebra} runs under a @sc{gnu} Hurd kernel it will act as a
 141 kernel routing table itself.  Under @sc{gnu} Hurd, all TCP/IP services are
 142 provided by user processes called @command{pfinet}.  Zebra will provide
 143 all the routing selection mechanisms for the process.  This feature will
 144 be implemented when @sc{gnu} Hurd becomes stable.
 145
 146 @node Supported Platforms, Supported RFC, System Architecture, Overview
 147 @comment  node-name,  next,  previous,  up
 148 @section Supported Platforms
 149
 150 @cindex Supported platforms
 151 @cindex Zebra on other systems
 152 @cindex Compatibility with other systems
 153 @cindex Operating systems that support Zebra
 154
 155   Currently Zebra supports @sc{gnu}/Linux, BSD and Solaris.  Below is a list
 156 of OS versions on which Zebra runs.  Porting Zebra to other platforms is
 157 not so too difficult.  Platform dependent codes exist only in
 158 @command{zebra} daemon.  Protocol daemons are platform independent.
 159 Please let us know when you find out Zebra runs on a platform which is not
 160 listed below.
 161
 162 @sp 1
 163 @itemize @bullet
 164 @item
 165 GNU/Linux 2.0.37
 166 @item
 167 GNU/Linux 2.2.x
 168 @item
 169 GNU/Linux 2.3.x
 170 @item
 171 FreeBSD 2.2.8
 172 @item
 173 FreeBSD 3.x
 174 @item
 175 FreeBSD 4.x
 176 @item
 177 NetBSD 1.4
 178 @item
 179 OpenBSD 2.5
 180 @item
 181 Solaris 2.6
 182 @item
 183 Solaris 7
 184 @end itemize
 185
 186 @sp 1
 187   Some IPv6 stacks are in development.  Zebra supports following IPv6
 188 stacks.  For BSD, we recommend KAME IPv6 stack.  Solaris IPv6 stack is
 189 not yet supported.
 190 @sp 1
 191 @itemize @bullet
 192 @item
 193 Linux IPv6 stack for GNU/Linux 2.2.x and higher.
 194 @item
 195 KAME IPv6 stack for BSD.
 196 @item
 197 INRIA IPv6 stack for BSD.
 198 @end itemize
 199
 200 @node Supported RFC, How to get Zebra, Supported Platforms, Overview
 201 @comment  node-name,  next,  previous,  up
 202 @section Supported RFC
 203
 204   Below is the list of currently supported RFC's.
 205
 206 @table @asis
 207 @item @asis{RFC1058}
 208 @cite{Routing Information Protocol. C.L. Hedrick. Jun-01-1988.}
 209
 210 @item @asis{RF2082}
 211 @cite{RIP-2 MD5 Authentication. F. Baker, R. Atkinson. January 1997.}
 212
 213 @item @asis{RFC2453}
 214 @cite{RIP Version 2. G. Malkin. November 1998.}
 215
 216 @item @asis{RFC2080}
 217 @cite{RIPng for IPv6. G. Malkin, R. Minnear. January 1997.}
 218
 219 @item @asis{RFC2328}
 220 @cite{OSPF Version 2. J. Moy. April 1998.}
 221
 222 @item @asis{RFC2740}
 223 @cite{OSPF for IPv6. R. Coltun, D. Ferguson, J. Moy. December 1999.}
 224
 225 @item @asis{RFC1771}
 226 @cite{A Border Gateway Protocol 4 (BGP-4). Y. Rekhter & T. Li. March 1995.}
 227
 228 @item @asis{RFC1965}
 229 @cite{Autonomous System Confederations for BGP. P. Traina. June 1996.}
 230
 231 @item @asis{RFC1997}
 232 @cite{BGP Communities Attribute. R. Chandra, P. Traina & T. Li. August 1996.}
 233
 234 @item @asis{RFC2545}
 235 @cite{Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing. P. Marques, F. Dupont. March 1999.}
 236
 237 @item @asis{RFC2796}
 238 @cite{BGP Route Reflection An alternative to full mesh IBGP. T. Bates & R. Chandrasekeran. June 1996.}
 239
 240 @item @asis{RFC2858}
 241 @cite{Multiprotocol Extensions for BGP-4. T. Bates, Y. Rekhter, R. Chandra, D. Katz. June 2000.}
 242
 243 @item @asis{RFC2842}
 244 @cite{Capabilities Advertisement with BGP-4. R. Chandra, J. Scudder. May 2000.}
 245
 246 @end table
 247
 248   When SNMP support is enabled, below RFC is also supported.
 249
 250 @table @asis
 251
 252 @item @asis{RFC1227}
 253 @cite{SNMP MUX protocol and MIB. M.T. Rose. May-01-1991.}
 254
 255 @item @asis{RFC1657}
 256 @cite{Definitions of Managed Objects for the Fourth Version of the
 257 Border Gateway Protocol (BGP-4) using SMIv2. S. Willis, J. Burruss,
 258 J. Chu, Editor. July 1994.}
 259
 260 @item @asis{RFC1724}
 261 @cite{RIP Version 2 MIB Extension. G. Malkin & F. Baker. November 1994.}
 262
 263 @item @asis{RFC1850}
 264 @cite{OSPF Version 2 Management Information Base. F. Baker, R. Coltun.
 265 November 1995.}
 266
 267 @end table
 268
 269 @node How to get Zebra, Mailing List, Supported RFC, Overview
 270 @comment  node-name,  next,  previous,  up
 271 @section How to get Zebra
 272
 273   Zebra is still beta software and there is no officially
 274 released version.  So currently Zebra is distributed from Zebra beta ftp
 275 site located at:
 276
 277 @url{ftp://ftp.zebra.org/pub/zebra}
 278
 279   Once Zebra is released you can get it from @sc{gnu} FTP site and
 280 its mirror sites.  We are planning Zebra-1.0 as the first released
 281 version.
 282
 283   Zebra's official web page is located at:
 284
 285 @url{http://www.gnu.org/software/zebra/zebra.html}.
 286
 287   There is a Zebra beta tester web page at:
 288
 289 @url{http://www.zebra.org/}.
 290
 291   You can get the latest beta software information from this page.
 292
 293 @node Mailing List, Bug Reports, How to get Zebra, Overview
 294 @comment  node-name,  next,  previous,  up
 295 @section Mailing List
 296 @cindex How to get in touch with Zebra
 297 @cindex Mailing Zebra
 298 @cindex Contact information
 299 @cindex Mailing lists
 300
 301   There is a mailing list for discussions about Zebra.  If you have any
 302 comments or suggestions to Zebra, please send mail to
 303 @email{zebra@@zebra.org}.  New snapshot announcements, improvement
 304 notes, and patches are sent to the list.
 305
 306   To subscribe to the @email{zebra@@zebra.org, Zebra mailing list},
 307 please send a mail to @email{majordomo@@zebra.org} with a message body
 308 that includes only:
 309
 310 @quotation
 311 subscribe zebra
 312 @end quotation
 313
 314   To unsubscribe from the list, please send a mail to
 315 @email{majordomo@@zebra.org} with a message body that includes only:
 316
 317 @quotation
 318 unsubscribe zebra
 319 @end quotation
 320
 321 @node Bug Reports,  , Mailing List, Overview
 322 @comment  node-name,  next,  previous,  up
 323 @section Bug Reports
 324
 325 @cindex Bug Reports
 326 @cindex Bug hunting
 327 @cindex Found a bug?
 328 @cindex Reporting bugs
 329 @cindex Reporting software errors
 330 @cindex Errors in the software
 331
 332   If you think you have found a bug, please send a bug report to
 333 @email{bug-zebra@@gnu.org}.  When you send a bug report, please be
 334 careful about the points below.
 335
 336 @itemize @bullet
 337 @item
 338 Please note what kind of OS you are using.  If you use the IPv6 stack
 339 please note that as well.
 340 @item
 341 Please show us the results of @code{netstat -rn} and @code{ifconfig -a}.
 342 Information from zebra's VTY command @code{show ip route} will also be
 343 helpful.
 344 @item
 345 Please send your configuration file with the report.  If you specify
 346 arguments to the configure script please note that too.
 347 @end itemize
 348
 349   Bug reports are very important for us to improve the quality of Zebra.
 350 Zebra is still in the development stage, but please don't hesitate to
 351 send a bug report to @email{bug-zebra@@gnu.org}.
 352