routing table 'time since last update'

[fran19422]

Just a simple question.

Within a routing table entry there is a time value immediately before the exit interface entry.

Does that time entry refer to the 'time since the last update' of that particular route ?

Thanks.

[Peter Paluch]

Hello Philip,

Does that time entry refer to the 'time since the last update' of that particular route ?

Yes, precisely.

You may notice that for event-driven protocols such as OSPF, IS-IS, EIGRP or BGP, the time may go up to days, weeks, even years if the network is that stable. For timer-driven protocols like RIP, this timer should always show a value lower than the Update interval (30 seconds by default for RIP), as in these protocols, the route is essentially reinstalled into the routing table each time an update arrives that confirms the existence of this network.

Best regards,

Peter