Dell Force10 E600i FTOS Version 8.4.1.5 Configuration Guide for ExaScale - Page 247

Timer values configured with the neighbor timers command override the timer values configured with the timers bgp command. When two neighbors, configured with different keepalive and holdtime values, negotiate for new values, the resulting values will be as follows: • the lower of the holdtime values is the new holdtime value, and • whichever is the lower value; one-third of the new holdtime value, or the configured keepalive value is the new keepalive value. BGP neighbor soft-reconfiguration Changing routing policies typically requires a reset of BGP sessions (the TCP connection) for the policies to take effect. This type of reset causes undue interruption to traffic due to the hard reset of the BGP cache and the time it takes to re-establish the session. BGP soft reconfiguration allows you to re-apply policies to a session without resetting the BGP session. You can perform soft reconfiguration on a per-neighbor basis for either inbound or outbound policies. BGP soft reconfiguration clears and reapplies policies without resetting the TCP connection. Use the clear ip bgp command in EXEC Privilege mode to reset a BGP connection using BGP soft reconfiguration. Command Syntax Command Mode Purpose neighbor {ipv4-address | ipv6-address | peer-group-name} soft-reconfiguration inbound CONFIG-ROUTER-BGP Enable inbound soft-reconfiguration for the specified BGP neighbor. BGP stores all updates received by the neighbor but does not reset the peer session. Entering this command starts the storage of updates on inbound routes, which is required for inbound soft reconfiguration. Outbound BGP soft reconfiguration does not require inbound soft reconfiguration to be enabled. clear ip bgp { * | as-number | ipv4neighbor-addr | ipv6-neighbor-addr | peer-group name} {ipv4 unicast | ipv4 multicast | ipv6 unicast} soft [in | out] EXEC Privilege Clears and reapplies policies on: *: All peers as-number: BGP routers that belong to the specified AS neighbor-addr: BGP neighbor with specified IP address Type of routes to be reapplied: ipv4 unicast, ipv4 multicast, or ipv6 unicast in: Reapplies only inbound policies out: Reapplies only outbound policies When inbound soft reconfiguration is enabled on a neighbor and you enter the clear ip bgp soft in command, the update database stored in the router is replayed and updates are reevaluated. The replay and update process is triggered only if a route-refresh request is not negotiated with the peer. If a route-refresh request is negotiated, BGP sends a request to the neighbor and receives all of the peer's updates. Border Gateway Protocol IPv4 (BGPv4) | 247