Dell EMC SmartFabric OS10 User Guide Release 10.5.0

Configure BFD for BGP

OS10 supports BFD sessions with IPv4 or IPv6 BGP neighbors using the default VRF. When you configure BFD for BGP, you can enable BFD sessions with all BGP neighbors discovered by BGP or with a specified neighbor.

1. Configure BFD session parameters and enable BFD globally on all interfaces in CONFIGURATION mode as described in Configure 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 configured in Step 1 are used.

   neighbor ip-address
     bfd
     no shutdown

   OR

   Configure BFD sessions with all neighbors discovered by the BGP in ROUTER-BGP mode. The BFD session parameters you configure override the global session parameters configured 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 configured bfd all-neighbors settings for a specified neighbor, enter the bfd disable command in ROUTER-NEIGHBOR mode.

   OR

   Enter a BGP template with neighborhood name in ROUTER-BGP mode. Configure BFD sessions with all neighbors which inherit the template in ROUTER-TEMPLATE mode. For more information on how to use BGP templates, see Peer templates. The global BFD session parameters configured in Step 1 are used.

   template template-name
     bfd
     no shutdown

4. Verify the BFD for BGP configuration in EXEC mode.

   show bfd neighbors [detail]

BFD for BGP all-neighbors configuration

OS10(conf)# bfd interval 200 min_rx 200 multiplier 6 role active
OS10(conf)# bfd enable
OS10(conf)# router bgp 4
OS10(config-router-bgp-4)# bfd all-neighbors interval 200 min_rx 200 multiplier 6 role active

BFD for BGP single-neighbor configuration

OS10(conf)# bfd interval 200 min_rx 200 multiplier 6 role active
OS10(conf)# bfd enable
OS10(conf)# router bgp 1
OS10(config-router-bgp-1)# neighbor 150.150.1.1 
OS10(config-router-neighbor)# bfd
OS10(config-router-neighbor)# no shutdown

BFD for BGP template configuration

OS10(config)# router bgp 300
OS10(config-router-bgp-300)# template ebgppg
OS10(config-router-template)# bfd
OS10(config-router-template)# exit
OS10(config-router-bgp-300)# neighbor 3.1.1.1
OS10(config-router-neighbor)# inherit template ebgppg
OS10(config-router-neighbor)# no shutdown

Display BFD operation

OS10# show bfd neighbors
* - Active session role
----------------------------------------------------------------------------
LocalAddr      RemoteAddr   Interface  State Rx-int Tx-int Mult VRF  Clients
----------------------------------------------------------------------------
* 150.150.1.2  150.150.1.1  vlan10     up    1000   1000   5   default  bgp

OS10# show bfd neighbors detail
Session Discriminator: 1
Neighbor Discriminator: 2
Local Addr: 150.150.1.2
Local MAC Addr: 90:b1:1c:f4:ab:fd
Remote Addr: 150.150.1.1
Remote MAC Addr: 90:b1:1c:f4:a4:d4
Interface: vlan10
State: up
Configured parameters:
TX: 1000ms, RX: 1000ms, Multiplier: 5
Actual parameters:
TX: 1000ms, RX: 1000ms, Multiplier: 5
Neighbor parameters:
TX: 200ms, RX: 200ms, Multiplier: 49
Role: active
VRF: default
Client Registered: bgp
Uptime: 01:58:09
Statistics:
  Number of packets received from neighbor: 7138
  Number of packets sent to neighbor: 7138

Verify BFD for BGP

OS10(config-router-bgp-101)# show ip bgp summary 
BGP router identifier 30.1.1.2 local AS number 101
Global BFD is enabled
Neighbor   AS    MsgRcvd    MsgSent    Up/Down    State/Pfx      
20.1.1.1   101   781        777        11:16:13     0         
30.1.1.1   101   787        779        11:15:35     0         

OS10(config-router-bgp-101)# show ip bgp neighbors 
BGP neighbor is 20.1.1.1, remote AS 101, local AS 101  internal link
  
  BGP version 4, remote router ID 30.1.1.1
  BGP state ESTABLISHED, in this state for 11:19:01
  Last read 00:24:31 seconds
  Hold time is 180, keepalive interval is 60 seconds
  Configured hold time is 180, keepalive interval is 60 seconds
  Fall-over disabled
  Neighbor is using Global level BFD Configuration
  
  Received 784 messages
    1 opens, 0 notifications, 0 updates
    783 keepalives, 0 route refresh requests
  Sent 780 messages
    2 opens, 0 notifications, 0 updates
    778 keepalives, 0 route refresh requests
  Minimum time between advertisement runs is 30 seconds
  Minimum time before advertisements start is 0 seconds
  Capabilities received from neighbor for IPv4 Unicast:
    MULTIPROTO_EXT(1)
    ROUTE_REFRESH(2)
    CISCO_ROUTE_REFRESH(128)
    4_OCTET_AS(65)
  Capabilities advertised to neighbor for IPv4 Unicast:
    MULTIPROTO_EXT(1)
    ROUTE_REFRESH(2)
    CISCO_ROUTE_REFRESH(128)
    4_OCTET_AS(65)
  Prefixes accepted 0, Prefixes advertised 0
  Connections established 1; dropped 0
  Last reset never
  For address family: IPv4 Unicast
    Allow local AS number 0 times in AS-PATH attribute
   Prefixes ignored due to:
    Martian address  0, Our own AS in AS-PATH 0
    Invalid Nexthop  0, Invalid AS-PATH length 0
    Wellknown community 0, Locally originated 0
  
  Local host: 20.1.1.2, Local port: 179
  Foreign host: 20.1.1.1, Foreign port: 58248