Eigrp active timer6/4/2023 Other possibilities that can bring the neighbor relationship down are unidirectional links, uncommon subnet mismatches, mismatched masks, layer 2 problems, ACL deny statement, etc. Perform "debug eigrp packet hello" on both routers to verify that the neighbors are ending and receiving EIGRP hello packets.Ĭheck the routing table entry to verify the next-hop address is correct for the neighbor.ģ. Are there any packet drops or timeĭoes the neighbor respond if you ping the EIGRP multicast address 224.0.0.10?Ģ. Ping, to the neighbor's directly connected interface IP address. Send a stream of 10000 count, once using 100 byte and once using 1500 byte packets,using extended R3 can not reply to R2’s query until it hears a reply from R4. If the router does not receive a reply to ALL its outstanding queries it will put the route in SIA (Stuck in Active) state and will kill the neighbor adjacency. The SIA timer on R2 reaches approximately 3 minutes. EIGRP is a reliable protocol and for each query, a router sends to its neighbors, it must get a reply in response within 3 minutes. "If no hellos are received within the hold time, which is 15 seconds by default on most links, the router informs the neighbor that the neighbor relationship has been torn down and logs a syslog message."ġ. You can see this problem by issuing either the show ip eigrp neighbor command or the show ip eigrp topology active command on R3 the queue count for R4 should be higher than usual. %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 10.51.254.2 (Vlan1)) is down: holding time expired If a hello packet is received, the hold timer resets. DUAL requires guaranteed and sequenced delivery for some transmissions. The IP multicast address used is 224.0.0.10. When no reply to a query is received, EIGRP sends an SIA query packet when the active timer is halfway through (after 90 seconds). All transmissions use IP with the protocol type field set to 88. The hold timer lasts as long as 3 times the hello interval, meaning the default is 15 seconds or 180 seconds on slow speed interfaces. The EIGRP transport mechanism uses a mix of multicast and unicast packets, using reliable delivery when necessary. This means the router did not receive an eigrp packet from its neighbor and the hold time expired,causing the neighbor to reset. EIGRP uses a timer called a hold timer, which is how long EIGRP determines the router to be working and reachable. The neighbor 10.51.254.2 is flapping up and down due to holding time expired.
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