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'Check Reachability' Function in BGP



Article ID: KB13540 KB Last Updated: 27 Mar 2009Version: 1.0

How does the Check Reachability option in the BGP instance actually check the reachability of specified network?


I set my default gateway IP address under the 'Check Reachability' section of the network option under BGP instance. How does the firewall use the 'Check Reachability' to determine if the network is reachable?

For example, in the WebUI, the following two ‘networks’ were added to Network > Routing > Virtual Router (BGP):

Network has 'Check Reachability' configured.

The corresponding CLI output is
set vrouter "trust-vr"
set protocol bgp 1
unset synchronization
set network no-check
set network check


BGP uses the routing table to see if there is an active route for that network. If there is an existing active route for that network, the firewall considers that network reachable. It does not work like monitoring where status pings are sent to that address.

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