Hats off to Dan, my co-worker….he’s been chasing a PRI issue at one of our new sites. He has a Cisco 2951 router with a VWIC3-1MFT-T1/E1 card installed, and when the PRI circuit is un-plugged and plugged back in, the circuit refuses to come up. However, if you reboot the router, the circuit will come up. (Rebooting the router is not a good fix, just in case you are wondering.)

As part of his troubleshooting, he replaced the VWIC3 card with a VWIC2 card and it works just fine…no issues. After working with Cisco TAC, he found out he was hitting a known bug with this VWIC3 card and IOS software (15.3(3)M6). At least the fix was easy…he simply had to add the command “hwic_t1e1 equalize” under the controller T1 interface…like this…

Adding in the hidden controller T1 command

What’s interesting is it’s a hidden command…if you list the available commands under controller T1 0/0/0, you won’t see this command…

A hidden command…interesting!

And I just bet there are a bunch more hidden commands that we don’t know about!!