User guide

Configuring a BGP Peer Configuring BGP
page 4-26 OmniSwitch AOS Release 7 Advanced Routing Configuration Guide March 2015
Configuring a BGP Peer
BGP supports two types of peers, or neighbors: internal and external. Internal sessions are run between
BGP speakers in the same autonomous system (AS). External sessions are run between BGP peers in
different autonomous systems. Internal neighbors may be located anywhere within the same autonomous
system while external neighbors are adjacent to each other and share a subnet. Internal neighbors may or
may not share a subnet.
BGP Peers can be configured on the OmniSwitch with the same AS number or different AS numbers.
Each peer must be explicitly configured on the OmniSwitch as BGP peers and are not dynamically
learned.
Note. In this document, the BGP terms “peer” and “neighbor” are used interchangeably to mean any BGP
entity known to the local router.
Peer Command Defaults
The following table lists the default values for many of the peer commands:
Parameter Description Command
Default Value/
Comments
Enables or disables BGP peer. ip bgp neighbor admin-state disabled
Assigns an AS number to the
BGP peer.
ip bgp neighbor remote-as 1
Configures the time interval for
updates between external BGP
peers.
ip bgp neighbor advertisement-interval 30
Enables or disables BGP peer
automatic restart.
ip bgp neighbor auto-restart enabled
Configures this peer as a client to
the local route reflector.
ip bgp neighbor route-reflector-client disabled
The interval, in seconds,
between
BGP retries to set up a
connection through the
transport protocol with another
peer.
ip bgp neighbor conn-retry-interval 120 seconds
Enables or disables BGP peer
default origination.
ip bgp neighbor default-originate disabled
Configures the tolerated hold
time interval, in seconds, for this
peer’s session, and timer interval
between KEEPALIVE messages
sent to this peer.
ip bgp neighbor timers hold time - 90 seconds
keep alive - 30 seconds
Configures the maximum number
of prefixes, or paths, the local
router can receive from this peer
in UPDATE messages.
ip bgp neighbor maximum-prefix 5000