IP default Gateway with C9400 (IOS-XE)

[Anouar ABDALLAH]

Hi guys,

We are configuring a Cisco Catalyst 9407 switch as a layer 2 switch so we have kept « ip routing » disabled and used « ip default-gateway » command for management traffic.

When we check routes with « show ip route » command, in output we see a default route pointing to the gateway used with « ip default-gateway ». Is it a normal behavior or we should see default gateway only in « show ip redirect » ?

[Deepak Kumar]

Hi,

Yes, It is normal behavior.

Regards,

Deepak Kumar

[Anouar ABDALLAH]

Thank you Deepak for your response. Is is related to IOS-XE or to particular versions?

[Reza Sharifi · Accepted solution]

Hi,

That is the correct behavior for all IOS versions and IOS XE. Now, if you want to use the out-of-band management port on the sup, you would need to put a default route inside the management vrf that points to the next hop. Example:

ip route vrf Mgmt-vrf 0.0.0.0 0.0.0.0 <next hop>

If your management is in-band, then what you see is correct. 

HTH

[Anouar ABDALLAH]

Thank you for explanation. I have just tested with 3650 and 3560. 3650 has a management VRF which can be used for OOB traffic (the management interface is configured with) and 3560 does not have. So for the first I found the default route in table and in the second I did not.

[Reza Sharifi]

The 3560 is an older model and did not come with an out-of-band management interface.  So, you have to use a vlan which is in-band. For 3560, you can use a default route or default gateway. If the switch is purely layer-2, all you need is a default gateway but if the switch is doing routing you would need a default route. On the 3650 (newer) there is an out-of-band management port that can be used. If you use that, you would need a default route in a vrf as I explained in the first post. If you don't add the default route, the management subnet will not be reachable from any other subnet.

HTH