4 Port EHWIC and VLANs stopped working and disappeared from the running-configuration

Thomas Ossman · ‎06-03-2016

I'm a WISP, I have a 2851 router at our head-end that has a 4 port EHWIC in one of it's slots with our wireless backup link, bandwidth manger's management interface, and power monitoring device plugging into it. A few hours ago I our network monitoring server sent out alerts saying that all those things were down, after sending someone out to ensure we hadn't lost power out there (we didn't) I started looking at the router.

I found that the EHWIC and the VLANs that are on those 4 interfaces are no where to be found in the running-config, and I mean completely gone, the interfaces are not listed, it's like the router does not know there is a card plugged in to it. I did a show diag and the router is reporting the the EHWIC is in the slot that it is in so it does seem to know it's there. The startup-config does have the 4 interfaces and VLANs configured correctly. So it seems that everything associated with the EHWIC just disappeared from the running-config.

We did have a rain storm role through about 2 hours before this happened, the box everything is in is water tight and has weathered much worse so I do not think it has anything to do with this but it is possible.

My plan right now is to wait until after business hours to power cycle the router, but I'm curious if there is anything else I can try doing, I'm just not sure where to start as I have never seen something like this happen before. Any help/insight would be greatly appreciated.

Philip D'Ath · ‎06-03-2016

I think I would try and remove the card, inspect it, and then re-seat it. This is not a hot swap card, so do it with the power removed.

This will also accomplish a router reboot as well. If that does not resolve it I think you have a dead card.

Note you can get Gigabit versions of these cards (EHWIC-4ESG) now for about the same price as well.

http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/qa_c67-612908.html

If you do need replacement hardware consider the Cisco 891F.

http://www.cisco.com/c/en/us/products/collateral/routers/800-series-routers/data_sheet_c78-519930.html

It comes with an 8 port Gigabit switch built in, a Gigabit WAN port, and a FastEthernet WAN port. With everything turned on (Firewall, NAT, IPSec, HQOS) it can flat line a 100Mb/s circuit. If you are doing just routing it gets a good 500Mb/s +. You can also get a rack mount bracket for it. They come with "Advanced IP", so can do BGP and pretty much every other protocol you would use. You can also get a PoE power supply for it to turn 4 of the 8 Gigabit ports into PoE ports. They are low power, and solid state (no moving parts like fans or anything). I hardly use routers like the 2851 anymore as a result unless I really need the module slots.

Best of all, they are a fraction of the cost of a 2851.