---
name: "exabgp"
section: "1"
platform: "linux"
package: "exabgp"
version: "4.2.25-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/exabgp"
---

# exabgp(1)

Influence or control network using BGP

## NAME

**exabgp** – Influence or control network using BGP

## SYNOPSIS

**exabgp** \[**--help** \| **-h**\] \[**--version** \| **-v**\] \[**--root** \| **-f**\] \[**--env** *env-config* \| **-e** *env-config*\] \[**--full-ini** \| **--fi**\] \[**--diff-ini** \| **--di**\] \[**--full-env** \| **--fe**\] \[**--diff-env** \| **--de**\] \[**--run** *helper*\] \[**--debug** \| **-d**\] \[**--validate**\] \[**--signal** *time*\] \[**--once** \| **-1**\] \[**--pdb** \| **-p**\] \[**--memory** \| **-s**\] \[**--profile** *profile*\] \[**--test** \| **-t**\] \[**--decode** *hex-message* \| **-x** *hex-message*\] \[*configuration* *...*\]

## DESCRIPTION

**exabgp** allows engineers to control their network from commodity servers. Possible uses include DDoS mitigation, network visualisation, service high availability and implementing anycast. **exabgp** does not perform any FIB manipulation on the system it runs on; if you need that this is not the program for you. **exabgp** can also print received BGP messages into readable plain text or JSON formatted text.

The arguments are as follows:

- **--help** \| **-h**

  Display summary of usage and configuration of exabgp.

- **--version** \| **-v**

  Display the **exabgp** version number and exit.

- **--root** *folder* \| **-f** *folder*

  Root folder where etc, bin, sbin are located.

- **--env** *env-config* \| **-e** *env-config*

  Specify where the environment configuration file can be found.

- **--full-ini** \| **--fi**

  Display the full environment configuration using on stdout using the ini format.

- **--diff-ini** \| **--di**

  Display the non-default environment configuration on stdout using the ini format.

- **--full-env** \| **--fe**

  Display the full environment configuration on stdout using the env format.

- **--diff-env** \| **--de**

  Display the non-default configuration on stdout using the env format.

- **--run** *helper*

  Do not run ExaBGP but one of its helper programs, options are: healthcheck and cli

- **--debug** \| **-d**

  Start the python debugger on serious logging on and on reception of the SIGTERM signal.   This is a shortcut for exabgp.log.all=true and exabgp.log.level=DEBUG.

- **--validate**

  Validate the configuration file format only.

- **--signal** *time*

  Issue a SIGUSR1 signal to reload the configuration after the specified number of seconds, only useful for code debugging.

- **--once** \| **-1**

  Only perform one attempt to connect to peers, used mostly for debugging.

- **--pdb** \| **-p**

  Start the python debugger on critical logging, reception of SIGTERM, and on uncaught python exceptions. This is a shortcut for exabgp.pdb.enable=true.

- **--memory** \| **-s**

  Display memory usage information on program exit.

- **--profile** *profile*

  Enable collection of profiling information to the given file. This is a shortcut for exabgp.profile.enable=true and exabgp.profile.file=profile.

- **--test** \| **-t**

  Only do a configuration validity check.

- **--decode** *hex-message* \| **-x** *hex-message*

  Decode a raw route packet in hexadecimal string.

## ENVIRONMENT

The configuration of exabgp is split in two:

- The environment configuration which controls the basic execution of **exabgp** such as logging, daemonizing, pid-file, profiling etc.

- The BGP configuration of exabgp, which specifies which neighbors it should talk BGP with and all other aspects of the BGP configuration.

The environment configuration can be specified a number of different ways, with different priority:

1. Command line values using dot-separated notation.

2. Environment variables using dot-separated notation.

3. Command line values using underscore-separated notation.

4. Environment variables using underscore-seprated notation.

5. The values from the ini configuration file, */etc/exabgp/exabgp.env*

6. The built-in default values.

The following environment variables can be used to configure the basic execution of **exabgp**:

- exabgp.api.encoder

  (experimental) default encoder to use with external API (text or json). Default: text.

- exabgp.api.highres

  Controls whether to use high-resolution timestamps in JSON. Default: false.

- exabgp.api.respawn

  Controls whether to respawn a helper process if it dies. Default: false.

- exabgp.bgp.openwait

  Controls how many seconds we should wait for a BGP open message once the TCP session is established. Default: 60 seconds.

- exabgp.cache.attributes

  Controls whether all attributes (configuration and wire) should be cached for faster parsing. Default: true.

- exabgp.cache.nexthops

  (deprecated) Controls whether route next-hops are cached. Default: true.

- exabgp.daemon.daemonize

  Controls whether **exabgp** should run in the background. Default: false.

- exabgp.daemon.pid

  Where to save the PID of **exabgp** if we manage it.   Default: '' (not set).

- exabgp.daemon.user

  The user to run **exabgp** as. Should be an unprivileged user. Default: nobody.

- exabgp.log.all

  Controls whether debug logging should be done for everything. Default: false.

- exabgp.log.configuration

  Controls whether logging should be done for the configuration and command parsing. Default: true.

- exabgp.log.daemon

  Controls whether logging should be done for PID change, forking, etc. Default: true.

- exabgp.log.destination

  Controls where logging should be sent. syslog (or no setting) sends the data to the local syslog server. host:\<location\> sends the data to a remote syslog server. stdout sends the data to stdout. stderr sends the data to stderr. \<filename\> sends the data to the named file. Default: stdout.

- exabgp.log.enable

  Controls whether logging should be done. Default: true.

- exabgp.log.level

  Sets the minimum severity level to log. Default: INFO.

- exabgp.log.message

  Controls logging of changes in route announcement in config reload. Default: false.

- exabgp.log.network

  Controls logging of networking information (TCP/IP state, network state etc.). Default: true.

- exabgp.log.packets

  Controls logging of BGP packets sent and received. Default: false.

- exabgp.log.parser

  Controls logging of BGP message parsing details. Default: false.

- exabgp.log.processes

  Controls logging of forked processes. Default: true.

- exabgp.log.reactor

  Controls logging of signals received and command reload. Default: true.

- exabgp.log.rib

  Controls logging of changes in locally configured routes. Default: false.

- exabgp.log.routes

  Controls logging of received routes. Default: false.

- exabgp.log.short

  Coontrols whether to use long or short log format (not prepended with time, level, pid and source). Default: false.

- exabgp.log.timers

  Controls logging of keepalive timers. Default: false.

- exabgp.pdb.enable

  Controls whether pdb, the python interactive debugger should be started on program faults. Default: false.

- exabgp.profile.enable

  Controls whether profiling of the code should be done. Default: false.

- exabgp.profile.file

  Controls where profiling results should be written. None/empty means stdout. Default: empty.

- exabgp.reactor.speed

  Controls the time of one reactor loop. Use only if you understand the code. Default: 1.0.

- exabgp.tcp.acl

  (experimental, unimplemented). Default: empty.

- exabgp.tcp.bind

  IP address to bind to when listening (no ip to disable). Default: empty.

- exabgp.tcp.delay

  Start to announce routes when the minutes in the hour is a modulo of this number. Default: 0.

- exabgp.tcp.once

  Only perform one TCP connection attempt per peer, for debugging scripts. Default: false.

- exabgp.tcp.port

  Port to bind to when listening. Default: 179.

## FILES

*/etc/exabgp/exabgp.env* is the default file for setting the "environment" variables controlling the execution of **exabgp**. An alaternative "env" configuration file can be supplied via the **--env** *env-config* argument. The format of this file is "Windows INI format". All the default settings can be shown with the **exabgp** **--test** **--full-init** command, an example showing parts of this output is:

```
[exabgp.api]
encoder = text
highres = false
respawn = false
[exabgp.bgp]
openwait = 60
```

Additionally, the user will need to supply a configuration file controlling the BGP configuration of **exabgp**, in the format described in [exabgp.conf(5)](/exabgp.conf/5.md).

## SIGNALS

**exabgp** catches a few different signals to control specific actions. They are:

- ALRM

  Restarts **exabgp**.

- USR1

  Causes **exabgp** to reload the configuration.

- USR2

  Causes **exabgp** to reload the configuration and restart any forked processes.

- TERM

  Terminates **exabgp**.

- HUP

  Also terminates **exabgp** (does  *not* reload the configuration anymore).

Reloading large configurations using signals is currently *not* recommended, because the configuration parsing code is currently blocking. Therefore if you have a large configuration change, it could cause the peer to miss some keepalive and cause a session flap.

## DIAGNOSTICS

The **--test** argument is useful to validate the syntax of the configuration file. The **--debug** flag will provide copious debug output to whereever the various exabgp.log variable settings dictate.

## SEE ALSO

[exabgp.conf(5)](/exabgp.conf/5.md)

## STANDARDS

A list of the standards **exabgp** implements which is indicative of the features implemented is:

- RFC 4893

  BGP Support for Four-octet AS Number Space

- RFC 4760

  Multiprotocol Extension for BGP-4

- RFC 4659

  BGP-MPLS IP Virtual Private Network (VPN) Extension for IPv6 VPN

- RFC 4762

  Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signalling

- RFC 5575

  Dissemination of Flow Specification Rules

- RFC 4724

  Graceful Restart Mechanism for BGP

- RFC 7313

  Enhanced Route Refresh Capability for BGP-4

- RFC 7311

  The Accumulated IGP Metric Attribute for BGP

- draft-raszuk-idr-flow-spec-v6-03

  (draft-ietf-idr-flow-spec-v6-06), Dissemination of Flow Specification Rules for IPv6

- draft-simpson-idr-flowspec-redirect-00 (-02)

  BGP Flow-Spec Redirect to IP Action

- draft-ietf-idr-flowspec-redirect-00 (-02)

  BGP Flow-Spec Redirect to IP Action

- draft-ietf-idr-add-paths-08 (-10)

  Advertisement of Multiple Paths in BGP

- draft-ietf-idr-bgp-multisession-07 (??)

  - draft-scudder-bmp-01 (??)

  A list of other more basic BGP-related standard entirely or partially implemented is:

- RFC 1997

  BGP Communities Attribute

- RFC 8092

  BGP Large Communities Attribute

- RFC 2385

  Protection of BGP Sessions via the TCP MD5 Signature

- RFC 2545

  Use of BGP-4 Multirptocol Extensions for IPv6 Inter-Domain Routing

- RFC 2918

  Route Refresh Capability for BGP-4

- RFC 3107

  Carrying Label Information in BGP-4

- RFC 3765

  NOPEER Community for Border Gateway Protocol (BGP) Route Scope Control

- RFC 7999

  BLACKHOLE BGP Community for Blackholing

- RFC 4271

  A Border Gateway Protocol 4 (BGP-4)

- RFC 4360

  BGP Extended Communities Attribute

- RFC 4364

  Constrained Route Distribution for BGP/MPLS IP VPNs

- RFC 4456

  BGP Rotue Relection: An Alternative to Full Mesh Internal BGP (iBGP)

- RFC 5396

  Textual Representation of Autonomous System (AS) Numbers

- RFC 5492

  Capabilities Advertisement with BGP-4

- RFC 6286

  Autonomous-System-Wide Unique BGP Identifier for BGP-4

- RFC 6608

  Subcodes for BGP Finate State Machine Error

- RFC 7752

  North-Bound Distribution of Link-State and Traffic Engineering (TE) Information Using BGP

- draft-gredler-idr-bgp-ls-segment-routing-ext-03

  BGP Link-State extensions for Segment Routing

- draft-ietf-idr-bgp-prefix-sid-05

  Segment Routing Prefix SID extensions for BGP