doc/user/overview.rst

   1 .. _overview:
   2
   3 ********
   4 Overview
   5 ********
   6
   7 `FRR`_ is a routing software package that provides TCP/IP based routing
   8 services with routing protocols support such as BGP, RIP, OSPF, IS-IS and more
   9 (see :ref:`supported-protocols`). FRR also supports
  10 special BGP Route Reflector and Route Server behavior.  In addition to
  11 traditional IPv4 routing protocols, FRR also supports IPv6 routing protocols.
  12 With an SNMP daemon that supports the AgentX protocol, FRR provides routing
  13 protocol MIB read-only access (:ref:`snmp-support`).
  14
  15 FRR uses an advanced software architecture to provide you with a high quality,
  16 multi server routing engine. FRR has an interactive user interface for each
  17 routing protocol and supports common client commands.  Due to this design, you
  18 can add new protocol daemons to FRR easily.  You can use FRR library as your
  19 program's client user interface.
  20
  21 FRR is distributed under the GNU General Public License.
  22
  23 FRR is a fork of `Quagga <http://www.quagga.net/>`_.
  24
  25 .. _about-frr:
  26
  27 About FRR
  28 =========
  29
  30 Today, TCP/IP networks are covering all of the world.  The Internet has been
  31 deployed in many countries, companies, and to the home.  When you connect to
  32 the Internet your packet will pass many routers which have TCP/IP routing
  33 functionality.
  34
  35 A system with FRR installed acts as a dedicated router.  With FRR, your machine
  36 exchanges routing information with other routers using routing protocols.  FRR
  37 uses this information to update the kernel routing table so that the right data
  38 goes to the right place.  You can dynamically change the configuration and you
  39 may view routing table information from the FRR terminal interface.
  40
  41 Adding to routing protocol support, FRR can setup interface's flags,
  42 interface's address, static routes and so on.  If you have a small network, or
  43 a stub network, or xDSL connection, configuring the FRR routing software is
  44 very easy.  The only thing you have to do is to set up the interfaces and put a
  45 few commands about static routes and/or default routes.  If the network is
  46 rather large, or if the network structure changes frequently, you will want to
  47 take advantage of FRR's dynamic routing protocol support for protocols such as
  48 RIP, OSPF, IS-IS or BGP.
  49
  50 Traditionally, UNIX based router configuration is done by *ifconfig* and
  51 *route* commands.  Status of routing table is displayed by *netstat* utility.
  52 Almost of these commands work only if the user has root privileges.  FRR has a
  53 different system administration method.  There are two user modes in FRR.  One
  54 is normal mode, the other is enable mode.  Normal mode user can only view
  55 system status, enable mode user can change system configuration.  This UNIX
  56 account independent feature will be great help to the router administrator.
  57
  58 Currently, FRR supports common unicast routing protocols, that is BGP, OSPF,
  59 RIP and IS-IS.  Upcoming for MPLS support, an implementation of LDP is
  60 currently being prepared for merging.  Implementations of BFD and PIM-SSM
  61 (IPv4) also exist, but are not actively being worked on.
  62
  63 The ultimate goal of the FRR project is making a production-grade, high
  64 quality, featureful and free IP routing software suite.
  65
  66
  67 System Architecture
  68 ===================
  69
  70 .. index:: System architecture
  71
  72 .. index:: Software architecture
  73
  74 .. index:: Software internals
  75
  76 Traditional routing software is made as a one process program which provides
  77 all of the routing protocol functionalities. FRR takes a different approach.
  78 FRR is a suite of daemons that work together to build the routing table. There
  79 is a daemon for each major supported protocol as well as a middleman daemon
  80 (*Zebra*) which serves as the broker between these daemons and the kernel.
  81
  82 This architecture allows for high resiliency, since an error, crash or exploit
  83 in one protocol daemon will generally not affect the others.  It is also
  84 flexible and extensible since the modularity makes it easy to implement new
  85 protocols and tie them into the suite.
  86
  87 An illustration of the large scale architecture is given below.
  88
  89 ::
  90
  91    +----+  +----+  +-----+  +----+  +----+  +----+  +-----+
  92    |bgpd|  |ripd|  |ospfd|  |ldpd|  |pbrd|  |pimd|  |.....|
  93    +----+  +----+  +-----+  +----+  +----+  +----+  +-----+
  94         |       |        |       |       |       |        |
  95    +----v-------v--------v-------v-------v-------v--------v
  96    |                                                      |
  97    |                         Zebra                        |
  98    |                                                      |
  99    +------------------------------------------------------+
 100           |                    |                   |
 101           |                    |                   |
 102    +------v------+   +---------v--------+   +------v------+
 103    |             |   |                  |   |             |
 104    | *NIX Kernel |   | Remote dataplane |   | ........... |
 105    |             |   |                  |   |             |
 106    +-------------+   +------------------+   +-------------+
 107
 108
 109 The multi-process architecture brings extensibility, modularity and
 110 maintainability. At the same time it also brings many configuration files and
 111 terminal interfaces. Each daemon has its own configuration file and terminal
 112 interface. When you configure a static route, it must be done in the *Zebra*
 113 configuration file. When you configure BGP network it must be done in the
 114 *bgpd* configuration file. This can become difficult to manage. To resolve the
 115 problem, FRR provides integrated user interface shell called *vtysh*. *vtysh*
 116 connects to each daemon with UNIX domain socket and then works as a proxy for
 117 user input.
 118
 119 Supported Platforms
 120 ===================
 121
 122 .. index:: Supported platforms
 123 .. index:: FRR on other systems
 124 .. index:: Compatibility with other systems
 125 .. index:: Operating systems that support FRR
 126
 127 Currently FRR supports GNU/Linux and BSD. Porting FRR to other platforms is not
 128 too difficult as platform dependent code should be mostly limited to the
 129 *Zebra* daemon. Protocol daemons are largely platform independent. Please let
 130 us know if you can get FRR to run on a platform which is not listed below:
 131
 132 - GNU/Linux
 133 - FreeBSD
 134 - NetBSD
 135 - OpenBSD
 136
 137 Versions of these platforms that are older than around 2 years from the point
 138 of their original release (in case of GNU/Linux, this is since the kernel's
 139 release on https://kernel.org/) may need some work.  Similarly, the following
 140 platforms may work with some effort:
 141
 142 - Solaris
 143 - MacOS
 144
 145 Recent versions of the following compilers are well tested:
 146
 147 - GNU's GCC
 148 - LLVM's Clang
 149 - Intel's ICC
 150
 151 .. _supported-protocols:
 152
 153 Supported Protocols vs. Platform
 154 ================================
 155
 156 The following table lists all protocols cross-refrenced to all operating
 157 systems that have at least CI build tests.  Note that for features, only
 158 features with system dependencies are included here.
 159
 160 .. role:: mark
 161
 162 .. comment - the :mark:`X` pieces mesh with a little bit of JavaScript and
 163    CSS in _static/overrides.{js,css} respectively.  The JS code looks at the
 164    presence of the 'Y' 'N' '≥' '†' or 'CP' strings.  This seemed to be the
 165    best / least intrusive way of getting a nice table in HTML.  The table
 166    will look somewhat shoddy on other sphinx targets like PDF or info (but
 167    should still be readable.)
 168
 169 +-----------------------------------+----------------+--------------+------------+------------+------------+
 170 | Daemon / Feature                  | Linux          | OpenBSD      | FreeBSD    | NetBSD     | Solaris    |
 171 +===================================+================+==============+============+============+============+
 172 | **FRR Core**                      |                |              |            |            |            |
 173 +-----------------------------------+----------------+--------------+------------+------------+------------+
 174 | `zebra`                           | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 175 +-----------------------------------+----------------+--------------+------------+------------+------------+
 176 |    VRF                            | :mark:`≥4.8`   | :mark:`N`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 177 +-----------------------------------+----------------+--------------+------------+------------+------------+
 178 |    MPLS                           | :mark:`≥4.5`   | :mark:`Y`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 179 +-----------------------------------+----------------+--------------+------------+------------+------------+
 180 | `pbrd` (Policy Routing)           | :mark:`Y`      | :mark:`N`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 181 +-----------------------------------+----------------+--------------+------------+------------+------------+
 182 | **WAN / Carrier protocols**       |                |              |            |            |            |
 183 +-----------------------------------+----------------+--------------+------------+------------+------------+
 184 | `bgpd` (BGP)                      | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 185 +-----------------------------------+----------------+--------------+------------+------------+------------+
 186 |    VRF / L3VPN                    | :mark:`≥4.8`   | :mark:`CP`   | :mark:`CP` | :mark:`CP` | :mark:`CP` |
 187 |                                   | :mark:`†4.3`   |              |            |            |            |
 188 +-----------------------------------+----------------+--------------+------------+------------+------------+
 189 |    EVPN                           | :mark:`≥4.18`  | :mark:`CP`   | :mark:`CP` | :mark:`CP` | :mark:`CP` |
 190 |                                   | :mark:`†4.9`   |              |            |            |            |
 191 +-----------------------------------+----------------+--------------+------------+------------+------------+
 192 |    VNC (Virtual Network Control)  | :mark:`CP`     | :mark:`CP`   | :mark:`CP` | :mark:`CP` | :mark:`CP` |
 193 +-----------------------------------+----------------+--------------+------------+------------+------------+
 194 |    Flowspec                       | :mark:`CP`     | :mark:`CP`   | :mark:`CP` | :mark:`CP` | :mark:`CP` |
 195 +-----------------------------------+----------------+--------------+------------+------------+------------+
 196 | `ldpd` (LDP)                      | :mark:`≥4.5`   | :mark:`Y`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 197 +-----------------------------------+----------------+--------------+------------+------------+------------+
 198 |    VPWS / PW                      | :mark:`N`      | :mark:`≥5.8` | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 199 +-----------------------------------+----------------+--------------+------------+------------+------------+
 200 |    VPLS                           | :mark:`N`      | :mark:`≥5.8` | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 201 +-----------------------------------+----------------+--------------+------------+------------+------------+
 202 | `nhrpd` (NHRP)                    | :mark:`Y`      | :mark:`N`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 203 +-----------------------------------+----------------+--------------+------------+------------+------------+
 204 | **Link-State Routing**            |                |              |            |            |            |
 205 +-----------------------------------+----------------+--------------+------------+------------+------------+
 206 | `ospfd` (OSPFv2)                  | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 207 +-----------------------------------+----------------+--------------+------------+------------+------------+
 208 |    Segment Routing                | :mark:`≥4.12`  | :mark:`N`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 209 +-----------------------------------+----------------+--------------+------------+------------+------------+
 210 | `ospf6d` (OSPFv3)                 | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 211 +-----------------------------------+----------------+--------------+------------+------------+------------+
 212 | `isisd` (IS-IS)                   | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 213 +-----------------------------------+----------------+--------------+------------+------------+------------+
 214 | **Distance-Vector Routing**       |                |              |            |            |            |
 215 +-----------------------------------+----------------+--------------+------------+------------+------------+
 216 | `ripd` (RIPv2)                    | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 217 +-----------------------------------+----------------+--------------+------------+------------+------------+
 218 | `ripngd` (RIPng)                  | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 219 +-----------------------------------+----------------+--------------+------------+------------+------------+
 220 | `babeld` (BABEL)                  | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 221 +-----------------------------------+----------------+--------------+------------+------------+------------+
 222 | `eigrpd` (EIGRP)                  | :mark:`Y`      | :mark:`Y`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 223 +-----------------------------------+----------------+--------------+------------+------------+------------+
 224 | **Multicast Routing**             |                |              |            |            |            |
 225 +-----------------------------------+----------------+--------------+------------+------------+------------+
 226 | `pimd` (PIM)                      | :mark:`≥4.18`  | :mark:`N`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 227 +-----------------------------------+----------------+--------------+------------+------------+------------+
 228 |    SSM (Source Specific)          | :mark:`Y`      | :mark:`N`    | :mark:`Y`  | :mark:`Y`  | :mark:`Y`  |
 229 +-----------------------------------+----------------+--------------+------------+------------+------------+
 230 |    ASM (Any Source)               | :mark:`Y`      | :mark:`N`    | :mark:`N`  | :mark:`N`  | :mark:`N`  |
 231 +-----------------------------------+----------------+--------------+------------+------------+------------+
 232
 233 The indicators have the following semantics:
 234
 235 * :mark:`Y` - daemon/feature fully functional
 236 * :mark:`≥X.X` - fully functional with kernel version X.X or newer
 237 * :mark:`†X.X` - restricted functionality or impaired performance with kernel version X.X or newer
 238 * :mark:`CP` - control plane only (i.e. BGP route server / route reflector)
 239 * :mark:`N` - daemon/feature not supported by operating system
 240
 241 .. _supported-rfcs:
 242
 243 Supported RFCs
 244 --------------
 245
 246 FRR implements the following RFCs:
 247
 248 .. note:: This list is incomplete.
 249
 250 - :rfc:`1058`
 251   :t:`Routing Information Protocol. C.L. Hedrick. Jun-01-1988.`
 252 - :rfc:`2082`
 253   :t:`RIP-2 MD5 Authentication. F. Baker, R. Atkinson. January 1997.`
 254 - :rfc:`2453`
 255   :t:`RIP Version 2. G. Malkin. November 1998.`
 256 - :rfc:`2080`
 257   :t:`RIPng for IPv6. G. Malkin, R. Minnear. January 1997.`
 258 - :rfc:`2328`
 259   :t:`OSPF Version 2. J. Moy. April 1998.`
 260 - :rfc:`2370`
 261   :t:`The OSPF Opaque LSA Option R. Coltun. July 1998.`
 262 - :rfc:`3101`
 263   :t:`The OSPF Not-So-Stubby Area (NSSA) Option P. Murphy. January 2003.`
 264 - :rfc:`2740`
 265   :t:`OSPF for IPv6. R. Coltun, D. Ferguson, J. Moy. December 1999.`
 266 - :rfc:`1771`
 267   :t:`A Border Gateway Protocol 4 (BGP-4). Y. Rekhter & T. Li. March 1995.`
 268 - :rfc:`1965`
 269   :t:`Autonomous System Confederations for BGP. P. Traina. June 1996.`
 270 - :rfc:`1997`
 271   :t:`BGP Communities Attribute. R. Chandra, P. Traina & T. Li. August 1996.`
 272 - :rfc:`2545`
 273   :t:`Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing. P.
 274   Marques, F. Dupont. March 1999.`
 275 - :rfc:`2796`
 276   :t:`BGP Route Reflection An alternative to full mesh IBGP. T. Bates & R.
 277   Chandrasekeran. June 1996.`
 278 - :rfc:`2858`
 279   :t:`Multiprotocol Extensions for BGP-4. T. Bates, Y. Rekhter, R. Chandra, D.
 280   Katz. June 2000.`
 281 - :rfc:`2842`
 282   :t:`Capabilities Advertisement with BGP-4. R. Chandra, J. Scudder. May 2000.`
 283 - :rfc:`3137`
 284   :t:`OSPF Stub Router Advertisement, A. Retana, L. Nguyen, R. White, A. Zinin,
 285   D. McPherson. June 2001`
 286 - :rfc:`4447`
 287   :t:`Pseudowire Setup and Maintenance Using the Label Distribution Protocol
 288   (LDP), L. Martini, E. Rosen, N. El-Aawar, T. Smith, and G. Heron. April
 289   2006.`
 290 - :rfc:`4762`
 291   :t:`Virtual Private LAN Service (VPLS) Using Label Distribution Protocol
 292   (LDP) Signaling, M. Lasserre and V. Kompella. January 2007.`
 293 - :rfc:`5036`
 294   :t:`LDP Specification, L. Andersson, I. Minei, and B. Thomas. October 2007.`
 295 - :rfc:`5561`
 296   :t:`LDP Capabilities, B. Thomas, K. Raza, S. Aggarwal, R. Aggarwal, and
 297   JL. Le Roux. July 2009.`
 298 - :rfc:`5918`
 299   :t:`Label Distribution Protocol (LDP) 'Typed Wildcard' Forward Equivalence
 300   Class (FEC), R. Asati, I. Minei, and B. Thomas. August 2010.`
 301 - :rfc:`5919`
 302   :t:`Signaling LDP Label Advertisement Completion, R. Asati, P. Mohapatra,
 303   E. Chen, and B. Thomas. August 2010.`
 304 - :rfc:`6667`
 305   :t:`LDP 'Typed Wildcard' Forwarding Equivalence Class (FEC) for PWid and
 306   Generalized PWid FEC Elements, K. Raza, S. Boutros, and C. Pignataro. July
 307   2012.`
 308 - :rfc:`6720`
 309   :t:`The Generalized TTL Security Mechanism (GTSM) for the Label Distribution
 310   Protocol (LDP), C. Pignataro and R. Asati. August 2012.`
 311 - :rfc:`7552`
 312   :t:`Updates to LDP for IPv6, R. Asati, C. Pignataro, K. Raza, V. Manral,
 313   and R. Papneja. June 2015.`
 314 - :rfc:`5880`
 315   :t:`Bidirectional Forwarding Detection (BFD), D. Katz, D. Ward. June 2010`
 316 - :rfc:`5881`
 317   :t:`Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop),
 318   D. Katz, D. Ward. June 2010`
 319 - :rfc:`5883`
 320   :t:`Bidirectional Forwarding Detection (BFD) for Multihop Paths, D. Katz,
 321   D. Ward. June 2010`
 322
 323 **When SNMP support is enabled, the following RFCs are also supported:**
 324
 325 - :rfc:`1227`
 326   :t:`SNMP MUX protocol and MIB. M.T. Rose. May-01-1991.`
 327 - :rfc:`1657`
 328   :t:`Definitions of Managed Objects for the Fourth Version of the Border
 329   Gateway Protocol (BGP-4) using SMIv2. S. Willis, J. Burruss, J. Chu, Editor.
 330   July 1994.`
 331 - :rfc:`1724`
 332   :t:`RIP Version 2 MIB Extension. G. Malkin & F. Baker. November 1994.`
 333 - :rfc:`1850`
 334   :t:`OSPF Version 2 Management Information Base. F. Baker, R. Coltun.
 335   November 1995.`
 336 - :rfc:`2741`
 337   :t:`Agent Extensibility (AgentX) Protocol. M. Daniele, B. Wijnen. January 2000.`
 338
 339 How to get FRR
 340 ==============
 341
 342 The official FRR website is located at |PACKAGE_URL| and contains further
 343 information, as well as links to additional resources.
 344
 345 Several distributions provide packages for FRR. Check your distribution's
 346 repositories to find out if a suitable version is available.
 347
 348 Mailing Lists
 349 =============
 350
 351 .. index:: How to get in touch with FRR
 352 .. index:: Contact information
 353 .. index:: Mailing lists
 354
 355
 356 Italicized lists are private.
 357
 358 +--------------------------------+------------------------------+
 359 | Topic                          | List                         |
 360 +================================+==============================+
 361 | Development                    | dev@lists.frrouting.org      |
 362 +--------------------------------+------------------------------+
 363 | Users & Operators              | frog@lists.frrouting.org     |
 364 +--------------------------------+------------------------------+
 365 | Announcements                  | announce@lists.frrouting.org |
 366 +--------------------------------+------------------------------+
 367 | *Security*                     | security@lists.frrouting.org |
 368 +--------------------------------+------------------------------+
 369 | *Technical Steering Committee* | tsc@lists.frrouting.org      |
 370 +--------------------------------+------------------------------+
 371
 372 The Development list is used to discuss and document general issues related to
 373 project development and governance. The public `Slack`_ instance and weekly
 374 technical meetings provide a higher bandwidth channel for discussions. The
 375 results of such discussions are reflected in updates, as appropriate, to code
 376 (i.e., merges), `GitHub issues`_ tracked issues, and for governance or process
 377 changes, updates to the Development list and either this file or information
 378 posted at `FRR`_.
 379
 380 Bug Reports
 381 ===========
 382
 383 For information on reporting bugs, please see :ref:`bug-reports`.
 384
 385 .. _frr: |package-url|
 386 .. _github: https://github.com/frrouting/frr/
 387 .. _github issues: https://github.com/frrouting/frr/issues
 388 .. _slack: https://frrouting.slack.com/