Connectivity Guide

BFD for BGP is supported only on directly connected BGP neighbors and in both BGP IPv4 and IPV6 networks. A maximum of 100
simultaneous BFD sessions are supported.
If each BFD for BGP neighbor receives a BFD control packet within the congured BFD interval for failure detection, the BFD session
remains up and BGP maintains its adjacencies. If a BFD for BGP neighbor does not receive a control packet within the detection interval,
the router informs any clients of the BFD session, and other routing protocols, about the failure. It then depends on the routing protocol
that uses the BGP link to determine the appropriate response to the failure condition. The normal response is to terminate the peering
session for the routing protocol and reconverge by bypassing the failed neighboring router. A log message generates whenever BFD
detects a failure condition.
Congure BFD for BGP
OS10 supports BFD sessions with IPv4 or IPv6 BGP neighbors using the default VRF. When you congure BFD for BGP, you can enable
BFD sessions with all BGP neighbors discovered by BGP or with a specied neighbor.
1 Congure BFD session parameters and enable BFD globally on all interfaces in CONFIGURATION mode as described in Congure BFD
globally.
bfd interval milliseconds min_rx milliseconds multiplier number role {active | passive}
bfd enable
2 Enter the AS number of a remote BFD peer in CONFIGURATION mode, from 1 to 65535 for a 2-byte AS number and from 1 to
4294967295 for a 4-byte AS number. Only one AS number is supported per system. If you enter a 4-byte AS number, 4-byte AS
support enables automatically.
router bgp as-number
3 Enter the IP address of a BFD peer in ROUTER-BGP mode. Enable a BFD session and the BGP link in ROUTER-NEIGHBOR mode.
The global BFD session parameters congured in Step 1 are used.
neighbor ip-address
bfd
no shutdown
OR
Congure BFD sessions with all neighbors discovered by the BGP in ROUTER-BGP mode. The BFD session parameters you congure
override the global session parameters congured in Step 1.
bfd all-neighbors [interval milliseconds min_rx milliseconds multiplier number role {active
| passive}]
• interval milliseconds — Enter the time interval for sending control packets to BFD peers, from 100 to 1000; default 200.
Dell EMC recommends using more than 100 milliseconds.
• min_rx milliseconds — Enter the maximum waiting time for receiving control packets from BFD peers, from 100 to 1000;
default 200. Dell EMC recommends using more than 100 milliseconds.
• multiplier number — Enter the maximum number of consecutive packets that are not received from a BFD peer before the
session state changes to Down, from 3 to 50; default 3.
• role {active | passive} — Enter active if the router initiates BFD sessions. Both BFD peers can be active at the same
time. Enter passive if the router does not initiate BFD sessions, and only responds to a request from an active BFD to initialize a
session. The default is
active.
To ignore the congured bfd all-neighbors settings for a specied neighbor, enter the bfd disable command in ROUTER-
NEIGHBOR mode.
OR
Layer 3
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