Interface Bonding on 2911

[michaelnilsson1]

Hello,

I have a cisco router 2911 with configured subinterfaces to allow for Inter-VLAN routing. My goal is to setup bonding (bundle, port-channel) on GE0/0 and GE0/1 to allow for redundancy in case of cable failure.

Because i set the channel-group on both GE0/0 and GE0/1 i would assume these interfaces are now bundled.

I do however need the encapsulation dot1Q and have 10.10.10.1 as default GW at all times. So I cant set on GE0/1.10

ip address 10.10.10.4 255.255.255.0

% 10.10.10.4 overlaps with GigabitEthernet 0/0.10

So after reading up on port-channel and dot1Q you can actually do

interface port-channel 1.10

On some routers, but not the 2911

Is there any way for me to get this working using port-channel or any other methods?

Heres my configuration

interface Port-Channel 1

   no ip address

!

interface GigabitEthernet 0/0

   no ip address

   channel-group 1

   duplex auto

   speed auto

!

interface GigabitEthernet 0/0.10

   encapsulation dot1Q 10

   ip address 10.10.10.4 255.255.255.0

   standby version 2

   standby 1 ip 10.10.10.1

   standby 1 priority 20

   standby 1 preempt

   standby 1 track GigabitEthernet 0/2

!

interface GigabitEthernet 0/0.20

   encapsulation dot1Q 20

   ip address 10.10.20.4 255.255.255.0

   standby version 2

   standby 1 ip 10.10.20.1

   standby 1 priority 20

   standby 1 preempt

   standby 1 track GigabitEthernet 0/2

!

interface GigabitEthernet 0/1

   no ip address

   channel-group 1

   duplex auto

   speed auto

!

interface GigabitEthernet 0/1.10

   encapsulation dot1Q 10

#  doesnt work

#   ip address 10.10.10.4 255.255.255.0

#   standby version 2

#   standby 1 ip 10.10.10.1

#   standby 1 priority 20

#   standby 1 preempt

#   standby 1 track GigabitEthernet 0/2

!

[Philip D'Ath · Accepted solution]

I just tested this on a 2911 running 15.4(3)M4 and it worked perfectly.  Config below.

When using port-channels layer 3 configuration should only be done on the "Port-Channel" interface.  You must remove any layer 3 configuration from the physical interfaces, and there should be no sub-interfaces configured (on the physical interfaces).

interface Port-channel1.10
 encapsulation dot1Q 10
 ip address 10.10.10.4 255.255.255.0

[Philip D'Ath]

ps. I guess it is possible this is a "licenced feature".  The 2911 I tested this on has an AppX licence (used to be called a "data" licence).  If you upgrade to 15.4(3)M4 and it doesn't work - that means you need the extra licence.

[michaelnilsson1]

Yes you are right!

Silly of me to try this in Packet Tracer before trying on the router itself.

Yes, interface port-channel1.10 worked without additional licenses.

Thank you