Inter VLAN ping doesnt work on C897

m.x · ‎12-24-2018

Hi, as a starting network engineer I am puzzled by a problem on of our clients has.. we cannot ping certain IPs within the network and others we can ping. This happens on a Cisco C897VAB-K9.

I’ve checked the ARP table and all IP register. But when I ping x.x.x.141 on vlan101 with source vlan 104 nothing happens, but when I ping x.x.x.135 on the same vlan from the same vlan104 the ping is successful. I also cannot ping any of the default gateways for those VLANs, which is strange because the x.x.x.135 is on VLAN 101.

So what am I missing here? The C897 router has Ethernet ports and vlans configured. It should in my opinion work..

some config:

interface Vlan101

ip address x.x.x.190 255.255.255.192

no ip redirects

no ip unreachables

no ip proxy-arp

ip nat inside

ip virtual-reassembly in

ip verify unicast reverse-path

ip tcp adjust-mss 1452

no autostate

interface Vlan104

ip address x.x.x.126 255.255.255.192

no ip redirects

no ip unreachables

no ip proxy-arp

ip nat inside

no ip virtual-reassembly in

ip verify unicast reverse-path

ip tcp adjust-mss 1452

no autostate

Georg Pauwen · ‎12-24-2018

Hello,

--> but when I ping x.x.x.35 on the same vlan from the same vlan104

I assume you mean x.x.x.135 ? Simply because .35 would not be in the same subnet.

Either way, post the full configuration of the router as well as the output of 'show ip route'...

Also check if the machines you cannot ping might be blocking ICMP through their firewalls...

paul driver · ‎12-24-2018

Hello

Suggest re-enable autostate and then make sure the clienst are able to respond to icmp quires

I am assume you have ip routing enabled on the L3 switch and disabled on the access switches?

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Kind Regards
Paul

m.x · ‎12-28-2018

Thanks for the reactions. I corrected te x.x.x.135 error in my post. I will try to post the config soon. I need to take out all the client information and keep it logical.

We are using an Cisco 897 which is a router/modem for average companies. It has a switch module integrated. I believe it uses the routers 4 LAN ports for routing. But correct me if I'm wrong.