L3 Etherchannel Routing Issue

[GregH.NY]

Hello. I have a lab where I created an L3 Etherchannel setup.

I am using two 3560 switches.

I was able to successfully configure the L3 Etherchannel but I can not ping the other switch.

I assume that I need to setup routing but have no routers. If so any suggestions how to set it up on the switches?

SW1

int vlan 1

ip add 10.0.0.1 255.255.255.0

no shut

int port-channel10

ip add 10.0.1.1 255.255.255.252

int range gig 0/45 - 48

no switchport

channel-group 10 mode on

SW2

int vlan 1

ip add 10.0.0.2 255.255.255.0

no shut

int port-channel10

ip add 10.0.1.2 255.255.255.252

int range gig 0/45 - 48

no switchport

channel-group 10 mode on

Any help is greatly appreciated

[mohammed01701]

Hi!

If this is only those subnet you use static routing but if you multible subnets on each the you have to use dynamic routing:

What you can do now is: 

Sw1

Ip route 0.0.0.0 0.0.0.0 10.0.1.1

Sw2

Ip route 0.0.0.0 0.0.0.0 10.0.1.2 

/Mohammed

[GregH.NY]

Thanks Mohammed. That makes sense.

I tried but I still can not ping the other switch through the L3 Etherchannel.

I verified that those IP route statements are in the running config.

[mohammed01701]

Hi! 

Which Interface have you VLAN 1?

Can you post show interface VLAN 1 on both switchs? Remember Interface vlan 1 has to be Up/up...

/Mohammed

[GregH.NY]

SW1

int vlan 1

ip add 10.0.0.1 255.255.255.0

no shut

SW2

int vlan 1

ip add 10.0.02 255.255.255.0

no shut

If I connect another cable between the switches they can ping each other fine so I know that the vlan 1 and ip addresses are fine. Just can not ping through the L3 Etherchannel

Thanks

[mohammed01701]

Hi!

If you want to ping the VLAN 1 IP address then the Interface has to be Up/Up?

/Mohammed

[GregH.NY]

Understood.

I just checked using Show ip int brief

VLAN1  status and protocol are UP/UP on both switches. 

[GregH.NY]

A little update:

I have not completely resolved the issue but this is what I found so far.

From SW1 (10.0.0.1/24) I can ping 10.0.1.1/30 which is the IP address I gave SW1 int. Port-channel 10

From SW1 (10.0.0.1/24) I can ping 10.0.1.2/30 which is the IP address I gave SW2 int. Port-channel 10

I just can not ping from SW1 (10.0.0.1/24) to SW2 (10.0.0.2/24)

Same as if I did this from SW2 to SW1.

Any more ideas greatly welcome.

Thanks

[GregH.NY]

Maybe this will help:

SW1                                                                SW2

VLAN1 10.0.0.1/24                                         VLAN1 10.0.0.2/24

Port-channel 10   10.0.1.1/30                         Port-channel 10   10.0.1.2/30

Can ping: 10.0.1.1 and 10.0.1.2                      Can ping: 10.0.1.2 and ping 10.0.1.1

Can not ping: 10.0.0.2                                     Can not ping: 10.0.0.1

[mohammed01701]

Hi!

Can you post show Interface VLAN 1 and show ip route on both switchs?

/Mohammed

[GregH.NY]

Sorry for the quality. In this facility I cant copy/paste from lab and get it to the internet.

I hope this helps

 

[Jon Marshall · Accepted solution]

You cannot route to the same IP subnet which is what you are trying to do. 

You have connected your switches together with a L3 connection so the vlan interfaces on each switch need to be in different subnets not the same subnet. 

Jon

[GregH.NY]

Good point Jon.

So I'm thinking that I would have to put SW2 in a separate subnet.

If so do I need to configure and IP Route or ACL?

[Jon Marshall]

You would need to add a route on each switch for the remote subnet. 

Jon

[GregH.NY]

Ahhh I see. Now it makes sense. The example I seen with L3 Etherchannel was not switch to switch but switch to server.

If my thinking is correct it would not make sense using L3 Etherchannel connections switch to switch because I would have to create additional networks, routes etc just to get the advantage of increased bandwidth of L3 Eth. Servers can be on a different network anyway so the example makes sense.

By the way I followed your advice and now it works. Just for practice reasons here is what I did to fix it.

SW1                                                                 SW2
int vlan 1                                                           int vlan 1
ip add 10.0.0.1 255.255.255.0                          ip add 10.0.99.1 255.255.255.0
exit                                                                    exit
interface port-channel 10                                  interface port-channel 10
ip add 10.0.1.1 255.255.255.0                          ip add 10.0.1.2 255.255.255.0
exit                                                                    exit
ip route 10.0.99.0 255.255.255.0 10.0.1.2        ip route 10.0.0.0 255.255.255.0 10.0.1.1

Thanks to you and everyone for your help!