Eigrp on layer 3 link

[suthomas1]

Hello,

A Site switch, which acts as the gateway for a small site is connected to distribution
switches with two uplinks in a port-channel. This then forms a eigrp relation with
the distribution switch over a L3 link (vlan 501).

I have pasted the relevant brief configurations below.
Question is-if one of the port-channel interfaces (eg Te 2/1/4) is down due to cable being
pulled out or manual shutdown, will eigrp try to do anything here? Flaps, reconvergence etc?
(considering that eigrp will load balance based on the src-dst concept which is not really
easy to figure out).

Appreciate all help on this please. Thanks in advance.

On the site switch >

interface Port-channel1
 description to Dist Switch(Te 1/1/4 & Te 2/1/4)
 switchport trunk native vlan 999
 switchport trunk allowed vlan 1,501
 switchport mode trunk
 ip dhcp snooping trust

interface TenGigabitEthernet1/1/4
 description to Dist Switch(Te 1/1/4)
 switchport trunk native vlan 999
 switchport trunk allowed vlan 1,501
 switchport mode trunk
 channel-group 1 mode active
 ip dhcp snooping trust

interface Vlan501
 description L3 link
 ip address 192.168.100.2 255.255.255.252
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip verify unicast source reachable-via rx
 ip pim sparse-mode

EIGRP-IPv4 VR(XXXX) Address-Family Neighbors for AS(XXXX)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
0   192.168.100.1              Vl501                    11 5w1d        3   100  0  50111

EIGRP-IPv4 VR(XXXX) Address-Family Neighbors for AS(XXXX)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
10  192.168.100.2              Vl501                    14 5w1d        5   100  0  5602

===============================

On the Distribution switch >

interface Port-channel1
 description to Site-1 switch(Te 1/1/4 & Te 2/1/4)
 switchport
 switchport trunk native vlan 999
 switchport mode trunk
 switchport trunk allowed vlan 1,501
 mtu 9216
 spanning-tree guard root

interface TenGigabitEthernet1/1/4
 description to Site-1 switch(Te 1/1/4)
 switchport
 switchport trunk native vlan 999
 switchport mode trunk
 switchport trunk allowed vlan 1,501
 mtu 9216
 spanning-tree guard root
 channel-group 1 mode active
 
interface Vlan501
 description L3 link
 ip address 192.168.100.1 255.255.255.252
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip pim sparse-mode
 

[Meheretab Mengistu · Accepted solution]

Question is-if one of the port-channel interfaces (eg Te 2/1/4) is down due to cable being pulled out or manual shutdown, will eigrp try to do anything here? Flaps, reconvergence etc?

No, EIGRP will not go through reconvergence. EIGRP could still send hello packets on the existing link, and the connectivity is still there from Layer 3 perspective.

HTH,
Meheretab

[Julio E. Moisa]

Nothing will happen, the EIGRP adjancency will work as normal, one of the functions of etherchannel is redundancy if a link fails the other links will be working as usual.

I assume the traffic is not too much over those links, so you could not have any problem.