Timers
The keep alive time specifies how frequently the device sends KEEPALIVE messages to its BGP4 neighbors. The hold time specifies how long the device waits for a KEEPALIVE or UPDATE message from a neighbor before concluding that the neighbor is dead. When the device concludes that a BGP4 neighbor is dead, the device ends the BGP4 session and closes the TCP connection to the neighbor.
A hold-time value of 0 means that the device waits indefinitely for messages from a neighbor without tearing down the session.
Note: Generally, you should set the hold time to three times the value of the keep alive
time.
Note: You can override the global keep alive time and hold time on individual neighbors.