Users Guide

• delayed configuration (the software at system boot reads the entire configuration file prior to sending messages to start BGP peer
sessions)
The following are not yet supported:
• auto-summarization (the default is no auto-summary)
• synchronization (the default is no synchronization)
BGP Configuration
To enable the BGP process and begin exchanging information, assign an AS number and use commands in ROUTER BGP mode to
configure a BGP neighbor.
By default, BGP is disabled.
By default, Dell Networking OS compares the MED attribute on different paths from within the same AS (the bgp always-compare-
med command is not enabled).
NOTE: In Dell Networking OS, all newly configured neighbors and peer groups are disabled. To enable a neighbor or peer
group, enter the neighbor {ip-address | peer-group-name} no shutdown command.
The following table displays the default values for BGP on Dell Networking OS.
Table 10. BGP Default Values
Item Default
BGP Neighbor Adjacency changes All BGP neighbor changes are logged.
Fast External Fallover feature Disabled
Graceful Restart feature Disabled
Local preference 100
MED 0
Route Flap Damping Parameters
half-life = 15 minutes
reuse = 750
suppress = 2000
max-suppress-time = 60 minutes
Distance
external distance = 20
internal distance = 200
local distance = 200
Timers
keepalive = 60 seconds
holdtime = 180 seconds
Add-path Disabled
Enabling BGP
By default, BGP is not enabled on the system. Dell Networking OS supports one autonomous system (AS) and assigns the AS number
(ASN).
To establish BGP sessions and route traffic, configure at least one BGP neighbor or peer.
In BGP, routers with an established TCP connection are called neighbors or peers. After a connection is established, the neighbors
exchange full BGP routing tables with incremental updates afterward. In addition, neighbors exchange KEEPALIVE messages to maintain
the connection.
In BGP, neighbor routers or peers can be classified as internal or external. External BGP peers must be connected physically to one
another (unless you enable the EBGP multihop feature), while internal BGP peers do not need to be directly connected. The IP address of
Border Gateway Protocol IPv4 (BGPv4)
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