8861 phones not coming up after an extended power outage

[spfister336]

We have several 8861 phones. After an extended (8 hour) power outage for electrical maintenance to the building, a random group of these phones failed to boot properly. After troubleshooting, it appears that the phones can reach their default gateway, but nothing beyond that. These phones do all get valid ip addresses, subnet masks, and default gateways through DHCP. Other phones connected to the same switch stack have no problems at all. 

As a workaround, we have found that by reserving the ip addresses of the non-working phones in DHCP, and rebooting the phones to force them to use a different address, the problem is fixed.  If we place a laptop on the network at the old address that the phone had will show the same problem (can get to default gateway, not beyond).

Has anyone seen anything like this?

[Roger Kallberg]

Sounds like you could have an ACL that blocks these specific IPs from communicating.

[spfister336]

No... no access lists at all on this VLAN. All phones worked great before the power outage.

[Roger Kallberg]

As a computer also has the same problem if it has the same IP as the phone had when it has problem it’s an indication that something makes the traffic not go through all the way from this IP. You would need to follow the entire path from A to B to see what’s up with this.

[George Sotiropoulos]

Considering that you face the same problem while testing with your laptop, you will need to identify if routing is fine on your network and you haven't missed upon reboot any kind of Access-List or "ip route" command on your core equipment. Are you aware when you last save the "running-config" on your network devices?

[spfister336]

The SVI for this VLAN is on a particular pair of 4500Xs. I can plug a laptop into a port on one of the switches, place it in the VLAN, and reproduce the problem. I don't think it's a routing issue, since the majority of devices in this VLAN work just fine.