![]() If there is still no reply the neighbour adjacency is dropped. This process can repeat three times, allowing three SIA-Query packets to be sent. If it is then the active timer is reset, giving the neighbour more time. The neighbour should immediately reply with an SIA-Reply packet stating if it is still waiting for a reply from its neighbour. 90 seconds) then the router will send the neighbour a SIA-Query asking if the neighbour is still working on the query. This is not ideal, as all networks learnt from the neighbour are flushed from the routing table.įor more recent versions of EIGRP, if the neighbour does not reply within half the active timer (i.e. R1(config-router-af-topology)#timers active-time ?ĭisabled disable time limit for active stateįor older versions of EIGRP if a reply is not received within the designated time, then the destination network is put into the stuck in active state and the neighbour adjacency is torn down. This has a default value of 3 minutes, but can be changed with the timers active-time command. When a query is first sent out an active timer is started. If the neighbours fail to respond (perhaps due to a an overloaded router, congestion, or an excessively large network) then the router becomes stuck in an active state.įortunately EIGRP has a few ways to deal with this issue. Consequently the original neighbour becomes dependant on it’s neighbour and its neighbour’s neighbour. If the neighbour has also lost its path to the destination, then it must also transition to an active state and wait for a response from its neighbour. ![]() It must wait for a reply before it can complete its diffusing computation and determine a new best path. ![]() If for some reason the destination is no longer reachable then the status of the network transitions to active.Īt this point the router queries its neighbour to determine if its neighbour still has a route to the destination. R1#show ip eigrp topologyĮIGRP-IPv4 VR(bottom) Topology Table for AS(100)/ID(10.1.1.1)Ĭodes: P - Passive, A - Active, U - Update, Q - Query, R - Reply, When EIGRP networks are fully converged they are in the passive state. If you’ve ever been in a networking interview, a question that frequently comes up is “what’s your understanding of stuck in active?” – well here’s an explanation.
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