Issue with intervaln routing with our CBS 350 switches.

[BremmerV]

This is related to a previous issue I posted here "titled issue-getting reply traffic back from our cbs 350 switches".

I have three VLANs defined on our CBS350 switches and sub-interfaces configured on our router (PaloAlto firewall) with all policies that allow traffic between the VLANS.

On the switch I have one IPv4 interface configured for VLAN 10 (10.10.10.4) and one default static route on the switch (0.0.0.0/0 out int. 10.10.10.1). I can be on VLAN 20 and get to VLAN 10 address 10.10.10.4 no problem, but If I jump on VLAN 10 and try to get to a VLAN 20 address it doesn't work. Or any other VLAN for that matter.

I tried adding an IPv4 address for vlan 20 (10.10.20.4) but as soon as I do this I can no longer get to the VLAN 10 address from VLAN 20. I tried adding a second quad 0 default route with the out int. as 10.10.20.1 but this failed to work. I do have "enable IP routing" selected on the IPv4 interface page. Im really not sure what the issue is here. Looking to see if anyone might have an answer.

Thanks,

[KJK99 · Accepted solution]

If you want a router-on-a-stick configuration, you do not need to enable the IPv4 routing on the switch or create extra SVIs there. If you do this, you may run into issues caused by asymmetric routing. All you need is to connect the switch and router using trunk ports and have your client devices connected to access ports and use the virtual interfaces set up on the router as their default gateways.

[BremmerV]

Hey KJK99,

Disabling IP routing seems to have done the trick. I still have a little more testing to do but this is looking resolved now. I'll go ahead and set this as the solution.

Thanks, for your help!!!

[Blue_Bird]

Hello BremmerV,

Please go through the follwing link...that helps you to enable Inter-vlan routing...

https://www.youtube.com/watch?v=g1NMbrnJfvg

Best regards
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