exabgp - Man Page

Influence or control network using BGP


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 ...]


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 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.


The configuration of exabgp is split in two:

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:


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


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


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


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


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


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


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


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


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


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


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


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


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.


Controls whether logging should be done. Default: true.


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


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


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


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


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


Controls logging of forked processes. Default: true.


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


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


Controls logging of received routes. Default: false.


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


Controls logging of keepalive timers. Default: false.


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


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


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


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


(experimental, unimplemented). Default: empty.


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


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


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


Port to bind to when listening. Default: 179.


/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:

encoder = text
highres = false
respawn = false

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


Restarts exabgp.


Causes exabgp to reload the configuration.


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


Terminates exabgp.


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.


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



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-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


BGP Link-State extensions for Segment Routing


Segment Routing Prefix SID extensions for BGP

Referenced By


February 26, 2015