eigrp flap

Hello, expert. during the lab study, I met eigrp bouncing as shown
below,.. after isolation, the problem was resolved with removing "ip
hello-interval eigrp 100 10" on each site. feel weird since my
understanding was the interval tuning does not bring impact the
adjacency in the eigrp case... Could anyone kindly explain the
mechanism and his(DUAL) logic?

*Mar 1 00:20:49.039: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.5 (Vlan30) is down: Peer
*Mar 1 00:20:49.063: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is down: Peer
*Mar 1 00:20:50.859: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is up: new adj
*Mar 1 00:20:50.863: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.5 (Vlan30) is up: new adj
*Mar 1 00:20:57.995: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is down: Peer
*Mar 1 00:21:00.363: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is up: new adj
*Mar 1 00:21:07.491: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is down: Peer
*Mar 1 00:21:10.123: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is up: new ad
*Mar 1 00:21:16.623: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is down: Peer
*Mar 1 00:21:19.731: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is up: new ad
*Mar 1 00:21:26.515: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is down: Peer
*Mar 1 00:21:26.535: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is down: Peer
*Mar 1 00:21:28.971: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is up: new adj
*Mar 1 00:21:28.975: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.30 (Vlan30) is up: new ad
*Mar 1 00:21:34.079: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor
135.15.20.4 (Vlan30) is down: Peer

RouterA(config-if)#do show ip eigrp int de
IP-EIGRP interfaces for process 100

                         Xmit Queue Mean Pacing Time Multicast
Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer
Routes
Vl30 4 0/0 85 0/1 408 0
   Hello interval is 10 sec
   Next xmit serial <none>
   Un/reliable mcasts: 0/109 Un/reliable ucasts: 428/303
   Mcast exceptions: 50 CR packets: 44 ACKs suppressed: 58
   Retransmissions sent: 20 Out-of-sequence rcvd: 18
   Authentication mode is md5, key-chain is "KEY"
   Use multicast

RouterB(config-if)#do show ip eigrp int de
IP-EIGRP interfaces for process 100

                         Xmit Queue Mean Pacing Time Multicast
Pending
Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer
Routes
Fa0/0 4 0/0 327 0/10 1244 0
   Hello interval is 10 sec
   Next xmit serial <none>
   Un/reliable mcasts: 0/338 Un/reliable ucasts: 1235/736
   Mcast exceptions: 43 CR packets: 39 ACKs suppressed: 189
   Retransmissions sent: 134 Out-of-sequence rcvd: 122
   Authentication mode is md5, key-chain is "KEY"

RouterA(config-router)#do show run | sec router eigrp
router eigrp 100
  network 135.15.20.0 0.0.0.255
  auto-summary

RouterB(config-router)#do show run | sec router eigrp
router eigrp 100
  network 135.15.20.0 0.0.0.255
  auto-summary

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Received on Wed Apr 11 2012 - 01:05:06 ART