I have a question that may make me sound dumb.
We have a Cisco 7206 router connected to a Cisco 6513(switchA) switch on vlan92. The switchA is connected to switchB over an etherchannel trunk.
switchA & B both have vlan92 SVI's.
When I check on the router, I can see both the switchA & B vlan92 addresses as EIGRP neighbours to the router. I thought EIGRP neighbours are formed only between directly connected routers or routers conenyed via a GRE tunnel. Can someone explain why this behaviour?
Router#sh ip eigrp nei
IP-EIGRP neighbors for process 50
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
5 10.3.92.254 Fa2/0 11 1d09h 1 300 0 1506856
4 10.3.92.253 Fa2/0 13 1d09h 1 300 0 159245
10.3.92.254- switchB VLAN92 SVI
10.3.92.253- switchA VLAN92 SVI.
Router is directly connected to switchA on Gig 9/45 which is in vlan92.
EIGRP uses multicast address 18.104.22.168 to communicate by default. Any EIGRP enabled router in the same network (same VLAN) will respond to this multicast address, and this is why routers in VLAN92 in your environment will establish neighbor relationship.