Configuring a BGP ConnectRetry Timer

You can control the speed at which BGP peer relationships are established by changing the BGP ConnectRetry timer value.

Context

After BGP initiates a TCP connection, the ConnectRetry timer will be stopped if the TCP connection is established successfully. If the first attempt to establish a TCP connection fails, BGP tries again to establish the TCP connection after the ConnectRetry timer expires.

Setting a short ConnectRetry interval reduces the period BGP waits between attempts to establish a TCP connection. This speeds up the establishment of the TCP connection.
Setting a long connectRetry interval suppresses routing flapping caused by peer relationship flapping.

A ConnectRetry timer can be configured either for all peers or peer groups, or for a specific peer or peer group. A ConnectRetry timer configured for a specific peer takes precedence over that configured for the peer group of this peer. In addition, a ConnectRetry timer configured for a specific peer or peer group takes precedence over that configured for all peers or peer groups.

Procedure

Configure a BGP ConnectRetry timer for all peers or peer groups.
1. Access the system view.
  system-view
2. Access the BGP view.
  bgp { as-number-plain | as-number-dot }
3. Set a BGP ConnectRetry timer for all peers or peer groups.
  timer connect-retry connect-retry-time
  
  By default, the ConnectRetry timer value is 32s.
Configure a ConnectRetry timer for a specific peer or peer group.
1. Access the system view.
  system-view
2. Access the BGP view.
  bgp { as-number-plain | as-number-dot }
3. Set a ConnectRetry timer for a specific peer or peer group.
  peer { group-name | ipv4-address } timer connect-retry connect-retry-time
  
  By default, the ConnectRetry timer value is 32s.
  
  The ConnectRetry timer configured for a peer or peer group takes precedence over that configured for all peers or peer groups.