Can't ping certain IPs from different subnet only from one switch?

natecarpenter · ‎01-06-2015

So I have a really strange issue and was wondering if you all could give me a hand...

I have two switches and an edge router at a customer's site using 3 seperate VLANs. I did not architect I just have to get it to work. The core switch is a 3560 and the access switch is a 3850.

Vlan 1: 172.21.21.0/24

Vlan 210: 10.64.40.0/23

Vlan 240: 172.23.135.38/27

Edge router: 172.21.21.1

So the big issue is the core switch cannot ping certain devices on vlan 1 from vlan 210 but the switch connected to it (WS01) can ping those exact same devices from vlan 210, the biggest example is the edge router, if i ping from the core switch using vlan 210 as a source it cannot reach it but if i ping from the connect access switch using vlan 210 as a source it will work just fine. In addition if I ping something like... 172.21.21.2 from vlan 210 on the core it works just fine. I'm not quite sure what I'm missing but I have no idea what it going on in this one.

paul driver · ‎01-06-2015

Hello

Do you have ip routing enabled on 3560 acting as the core switch?
Also disable ip routing on the 3850 if this is just acting as a host switch and make sure it uses a default-gateway instead.

res

Paul

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Paul

natecarpenter · ‎01-06-2015

I have ip routing enabled on both currently, is there any reason I should not?

paul driver · ‎01-06-2015

Hello

Yes, as the 3850 is only acting as a host switch meaning it should not be doing any routing and with routing enabled it try to lookup destination addresses it cannot find in its route table of which I guess there isn't anything entered unless you have a static routes.

So this switch should just have a default-gateway pointing to the 3560 svi interface for it management vlan and ip routing disabled.

Just to verify the 3560 has multiple SVI interfaces for each vlan and I trunk interconnect to the 3850?

res

Paul

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Paul

natecarpenter · ‎01-06-2015

Correct, the 3850 has 2 trunks in a port-channel connecting to the 3560, and the 3850 can ping all 3 of the seperate SVIs on the core as well as any IP on any subnet.

paul driver · ‎01-06-2015

Hello

Okay then, I would try and disable ip routing on the 3850 then make sure all vlans are allowed across the trunks and the vtp database populated with all vlans. on all switches?

then test again.

res

Paul

n

Please rate and mark as an accepted solution if you have found any of the information provided useful.
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Kind Regards
Paul