Interface Status

Whenever the decision maker changes the status of a BGP peering to down, or the status is unknown and the require-bgp-snmp-poll command is disabled, the decision maker will check the status of the interface before taking action.

When interface-status polling is enabled, interface status can have one of these values:

• up--the decision maker will consider the link to still be usable even though the BGP peering was marked unknown
• down--if the link is reported to be down consecutively a user-determined number of times (configured with the polling interface-status down-threshold command) plus one, the link will be considered unusable until status of either the interface or the BGP peering changes
• unknown--if the interface status is reported as unknown, no change will be made to the link’s status

BGP and interface status are independently configured and can therefore be enabled or disabled independently of each other.

However, if BGP polling is not enabled, BGP status will always be considered up, and the interface status will never be checked.

If BGP polling is enabled and interface polling is not, the interface status will be unknown and the link status will always remain unchanged from whatever state it was in when the interface status was checked.

NOTE: In addition to the unknown threshold values for BGP and interface status, you can also configure the number of times the CNA system will attempt to get data from the SNMP agent before it reports status to be unknown; see the polling snmp-agent and retries commands.