3850 Switch Routing and CEF enabled but ip routing is disabled

[Carlo Pablo Torres]

Hi Cisco Support Community,

I encountered a weird scenario where ip routing is disabled in 3850 switch but routing table and ip cef exists.

servers A ------------ router A <---------------------->  3850 <-----------------------------> router B ----------- servers B


Issue
Servers A can't communicate to servers B but from 3850 we can reach servers B when we tried configuring a loopback with an IP address from server A

ip routing is disabled in 3850 and just static routing.

I also know there is an associated bug for this which is CSCut37113 but seems 3850 is doing routing even when ip routing is disabled from our test.

Is this a bug on the 3850 where routing does not work when it receives routes from outside? And how it's supposed to build its cef table when ip routing is supposed to be disabled.

I am confused because from the loopback test I assume it's already doing route lookup.

Thanks!

[Carlo Pablo Torres]

I think I got it

If i am not mistaken, 3850 will not do route lookup for locally sourced traffic so it does it need not look at the routing table to forward the packet but instead it just do arp then forwards it to gateway router B. Correct me if I am wrong :)