@node Overview, Installation, Top, Top @comment node-name, next, previous, up @chapter Overview @cindex Overview Zebra is a routing software package that provides TCP/IP based routing services with routing protocols support such as RIPv1, RIPv2, RIPng, OSPFv2, OSPFv3, BGP-4, and BGP-4+ (@pxref{Supported RFC}). Zebra also supports special BGP Route Reflector and Route Server behavior. In addition to traditional IPv4 routing protocols, Zebra also supports IPv6 routing protocols. With SNMP daemon which supports SMUX protocol, Zebra provides routing protocol MIBs (@pxref{SNMP Support}). Zebra uses an advanced software architecture to provide you with a high quality, multi server routing engine. Zebra has an interactive user interface for each routing protocol and supports common client commands. Due to this design, you can add new protocol daemons to Zebra easily. You can use Zebra library as your program's client user interface. Zebra is an official @sc{gnu} software and distributed under the @sc{gnu} General Public License. @menu * About Zebra:: Basic information about Zebra * System Architecture:: The Zebra system architecture * Supported Platforms:: Supported platforms and future plans * Supported RFC:: Supported RFCs * How to get Zebra:: * Mailing List:: Mailing list information * Bug Reports:: Mail address for bug data @end menu @node About Zebra, System Architecture, Overview, Overview @comment node-name, next, previous, up @section About Zebra @cindex About Zebra Today, TCP/IP networks are covering all of the world. The Internet has been deployed in many countries, companies, and to the home. When you connect to the Internet your packet will pass many routers which have TCP/IP routing functionality. A system with Zebra installed acts as a dedicated router. With Zebra, your machine exchanges routing information with other routers using routing protocols. Zebra uses this information to update the kernel routing table so that the right data goes to the right place. You can dynamically change the configuration and you may view routing table information from the Zebra terminal interface. Adding to routing protocol support, Zebra can setup interface's flags, interface's address, static routes and so on. If you have a small network, or a stub network, or xDSL connection, configuring the Zebra routing software is very easy. The only thing you have to do is to set up the interfaces and put a few commands about static routes and/or default routes. If the network is rather large, or if the network structure changes frequently, you will want to take advantage of Zebra's dynamic routing protocol support for protocols such as RIP, OSPF or BGP. Zebra is with you. Traditionally, UNIX based router configuration is done by @command{ifconfig} and @command{route} commands. Status of routing table is displayed by @command{netstat} utility. Almost of these commands work only if the user has root privileges. Zebra has a different system administration method. There are two user modes in Zebra. One is normal mode, the other is enable mode. Normal mode user can only view system status, enable mode user can change system configuration. This UNIX account independent feature will be great help to the router administrator. Currently, Zebra supports common unicast routing protocols. Multicast routing protocols such as BGMP, PIM-SM, PIM-DM will be supported in Zebra 2.0. MPLS support is going on. In the future, TCP/IP filtering control, QoS control, diffserv configuration will be added to Zebra. Zebra project's final goal is making a productive, quality free TCP/IP routing software. @node System Architecture, Supported Platforms, About Zebra, Overview @comment node-name, next, previous, up @section System Architecture @cindex System architecture @cindex Software architecture @cindex Software internals Traditional routing software is made as a one process program which provides all of the routing protocol functionalities. Zebra takes a different approach. It is made from a collection of several daemons that work together to build the routing table. There may be several protocol-specific routing daemons and zebra the kernel routing manager. The @command{ripd} daemon handles the RIP protocol, while @command{ospfd} is a daemon which supports OSPF version 2. @command{bgpd} supports the BGP-4 protocol. For changing the kernel routing table and for redistribution of routes between different routing protocols, there is a kernel routing table manager @command{zebra} daemon. It is easy to add a new routing protocol daemons to the entire routing system without affecting any other software. You need to run only the protocol daemon associated with routing protocols in use. Thus, user may run a specific daemon and send routing reports to a central routing console. There is no need for these daemons to be running on the same machine. You can even run several same protocol daemons on the same machine. This architecture creates new possibilities for the routing system. @example @group +----+ +----+ +-----+ +-----+ |bgpd| |ripd| |ospfd| |zebra| +----+ +----+ +-----+ +-----+ | +---------------------------|--+ | v | | UNIX Kernel routing table | | | +------------------------------+ Zebra System Architecture @end group @end example Multi-process architecture brings extensibility, modularity and maintainability. At the same time it also brings many configuration files and terminal interfaces. Each daemon has it's own configuration file and terminal interface. When you configure a static route, it must be done in @command{zebra} configuration file. When you configure BGP network it must be done in @command{bgpd} configuration file. This can be a very annoying thing. To resolve the problem, Zebra provides integrated user interface shell called @command{vtysh}. @command{vtysh} connects to each daemon with UNIX domain socket and then works as a proxy for user input. Zebra was planned to use multi-threaded mechanism when it runs with a kernel that supports multi-threads. But at the moment, the thread library which comes with @sc{gnu}/Linux or FreeBSD has some problems with running reliable services such as routing software, so we don't use threads at all. Instead we use the @command{select(2)} system call for multiplexing the events. When @command{zebra} runs under a @sc{gnu} Hurd kernel it will act as a kernel routing table itself. Under @sc{gnu} Hurd, all TCP/IP services are provided by user processes called @command{pfinet}. Zebra will provide all the routing selection mechanisms for the process. This feature will be implemented when @sc{gnu} Hurd becomes stable. @node Supported Platforms, Supported RFC, System Architecture, Overview @comment node-name, next, previous, up @section Supported Platforms @cindex Supported platforms @cindex Zebra on other systems @cindex Compatibility with other systems @cindex Operating systems that support Zebra Currently Zebra supports @sc{gnu}/Linux, BSD and Solaris. Below is a list of OS versions on which Zebra runs. Porting Zebra to other platforms is not so too difficult. Platform dependent codes exist only in @command{zebra} daemon. Protocol daemons are platform independent. Please let us know when you find out Zebra runs on a platform which is not listed below. @sp 1 @itemize @bullet @item GNU/Linux 2.0.37 @item GNU/Linux 2.2.x @item GNU/Linux 2.3.x @item FreeBSD 2.2.8 @item FreeBSD 3.x @item FreeBSD 4.x @item NetBSD 1.4 @item OpenBSD 2.5 @item Solaris 2.6 @item Solaris 7 @end itemize @sp 1 Some IPv6 stacks are in development. Zebra supports following IPv6 stacks. For BSD, we recommend KAME IPv6 stack. Solaris IPv6 stack is not yet supported. @sp 1 @itemize @bullet @item Linux IPv6 stack for GNU/Linux 2.2.x and higher. @item KAME IPv6 stack for BSD. @item INRIA IPv6 stack for BSD. @end itemize @node Supported RFC, How to get Zebra, Supported Platforms, Overview @comment node-name, next, previous, up @section Supported RFC Below is the list of currently supported RFC's. @table @asis @item @asis{RFC1058} @cite{Routing Information Protocol. C.L. Hedrick. Jun-01-1988.} @item @asis{RF2082} @cite{RIP-2 MD5 Authentication. F. Baker, R. Atkinson. January 1997.} @item @asis{RFC2453} @cite{RIP Version 2. G. Malkin. November 1998.} @item @asis{RFC2080} @cite{RIPng for IPv6. G. Malkin, R. Minnear. January 1997.} @item @asis{RFC2328} @cite{OSPF Version 2. J. Moy. April 1998.} @item @asis{RFC2740} @cite{OSPF for IPv6. R. Coltun, D. Ferguson, J. Moy. December 1999.} @item @asis{RFC1771} @cite{A Border Gateway Protocol 4 (BGP-4). Y. Rekhter & T. Li. March 1995.} @item @asis{RFC1965} @cite{Autonomous System Confederations for BGP. P. Traina. June 1996.} @item @asis{RFC1997} @cite{BGP Communities Attribute. R. Chandra, P. Traina & T. Li. August 1996.} @item @asis{RFC2545} @cite{Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing. P. Marques, F. Dupont. March 1999.} @item @asis{RFC2796} @cite{BGP Route Reflection An alternative to full mesh IBGP. T. Bates & R. Chandrasekeran. June 1996.} @item @asis{RFC2858} @cite{Multiprotocol Extensions for BGP-4. T. Bates, Y. Rekhter, R. Chandra, D. Katz. June 2000.} @item @asis{RFC2842} @cite{Capabilities Advertisement with BGP-4. R. Chandra, J. Scudder. May 2000.} @end table When SNMP support is enabled, below RFC is also supported. @table @asis @item @asis{RFC1227} @cite{SNMP MUX protocol and MIB. M.T. Rose. May-01-1991.} @item @asis{RFC1657} @cite{Definitions of Managed Objects for the Fourth Version of the Border Gateway Protocol (BGP-4) using SMIv2. S. Willis, J. Burruss, J. Chu, Editor. July 1994.} @item @asis{RFC1724} @cite{RIP Version 2 MIB Extension. G. Malkin & F. Baker. November 1994.} @item @asis{RFC1850} @cite{OSPF Version 2 Management Information Base. F. Baker, R. Coltun. November 1995.} @end table @node How to get Zebra, Mailing List, Supported RFC, Overview @comment node-name, next, previous, up @section How to get Zebra Zebra is still beta software and there is no officially released version. So currently Zebra is distributed from Zebra beta ftp site located at: @url{ftp://ftp.zebra.org/pub/zebra} Once Zebra is released you can get it from @sc{gnu} FTP site and its mirror sites. We are planning Zebra-1.0 as the first released version. Zebra's official web page is located at: @url{http://www.gnu.org/software/zebra/zebra.html}. There is a Zebra beta tester web page at: @url{http://www.zebra.org/}. You can get the latest beta software information from this page. @node Mailing List, Bug Reports, How to get Zebra, Overview @comment node-name, next, previous, up @section Mailing List @cindex How to get in touch with Zebra @cindex Mailing Zebra @cindex Contact information @cindex Mailing lists There is a mailing list for discussions about Zebra. If you have any comments or suggestions to Zebra, please send mail to @email{zebra@@zebra.org}. New snapshot announcements, improvement notes, and patches are sent to the list. To subscribe to the @email{zebra@@zebra.org, Zebra mailing list}, please send a mail to @email{majordomo@@zebra.org} with a message body that includes only: @quotation subscribe zebra @end quotation To unsubscribe from the list, please send a mail to @email{majordomo@@zebra.org} with a message body that includes only: @quotation unsubscribe zebra @end quotation @node Bug Reports, , Mailing List, Overview @comment node-name, next, previous, up @section Bug Reports @cindex Bug Reports @cindex Bug hunting @cindex Found a bug? @cindex Reporting bugs @cindex Reporting software errors @cindex Errors in the software If you think you have found a bug, please send a bug report to @email{bug-zebra@@gnu.org}. When you send a bug report, please be careful about the points below. @itemize @bullet @item Please note what kind of OS you are using. If you use the IPv6 stack please note that as well. @item Please show us the results of @code{netstat -rn} and @code{ifconfig -a}. Information from zebra's VTY command @code{show ip route} will also be helpful. @item Please send your configuration file with the report. If you specify arguments to the configure script please note that too. @end itemize Bug reports are very important for us to improve the quality of Zebra. Zebra is still in the development stage, but please don't hesitate to send a bug report to @email{bug-zebra@@gnu.org}.