SW cannot ping an interface located on the same switch

[garyrivers]

i have a 3750 SW that i have config-ed an interface VLAN102 (IP 10.35.40.254) and i cannot ping it. this SW was a master SW in a 2-SW chain and this interface has been around awhile.

here's the rub: the devices that have the 40.254 as a gateway cannot ping it either BUT they can ping a device outside of that VLAN.  in other words we did a tracert to a 10.35.45.1 and the trace went thru VLAN102 and on to the destination.

So, i'm really stumped as to WHY I cannot see that IP from the SW and why devices behind it cannot see it either but can trace thru it.

Any ideas?

Thanks, Gary

[Edison Ortiz]

Let's see the switch config along with show ip route, show ip interface brief | ex una and show vlan.

[garyrivers]

here's the requested info

[zhang_yang]

what is the configuration of int vlan 102? show run int vlan 102

Pick a host/device in VLAN 201 A which cannot ping 40.254,  check the output of ipconfig/all on host A.

ping A from the switch source from VLAN 102.

check the output of show ip arp "A's IP address" and show mac- add add "A's MAC"

show run int "the port connected to A"

ping from A to another device in VLAN 102 which is connected to the switch.

show log .

These are the first few things I want to check.

Post the output so that we can check.

[Richard Burts]

Gary

This is a bit of a puzzle. I am not sure that I have all of the answer. But I believe that I have part of it. I wonder why the devices can not ping 10.35.40.254. And I suspect that the suggestion to check the attached devices for address and gateway may help in understanding this.

But I believe that part of understanding the situation is to understand that VLANs 100 and 104 are active, even though there are no ports associated with them. I believe that this indicates that there is a trunk port on the switch (probably port Gi0/2/23). And the traffic from the other ports may be carried over the trunk to their gateway.

HTH

Rick

[garyrivers]

Rick,

So because of that trunk port going to SW28, VLAN102 & 3 are active. Mmmmmm

we attached a PC to one of the ports associated with VLAN 102 and we were still not able to ping the GW.

the attached PC has an IP of 10.35.40.108/24 and a GW of 10.35.40.254

[garyrivers]

Well, I just got off the phone with Cisco and what they did to resolve the issue was to insert “permit icmp any any” in to the “Production” and “P2NAS” ACLs.

They think the 12.1 IOS has a bug in it and, of course, they recommend upgrading to the latest; which I’m planning on, probably Monday.  I HATE doing stuff like that on a Friday.

Thanks for your help guys, i really appriciate your assistance.