Cisco 2811 Startup-Config Issue
We had the batteries in our small UPS replaced today and had to take everything down for about 30 minutes while they did whatever UPS people do. When everything came back up, for some reason that I have yet to determine, the startup and running configs were different. I checked the config register, and it was fine…hmph.
The startup config had int f0/0 configured correctly, but when the router booted, everything BUT f0/0 had the correct configuration. What was even more odd was that the IP address was originally 192.168.1.2/30, but when I tried to apply that to the interface (mind you, this was the IP that it had been currently been using), I got the “Bad mask /30″ error. Weird. I looked through the startup config and found that IP subnet zero was there as well.
I ran no ip subnet-zero, applied the IP address /30 to the interface, and it came right back up without any issues. Now, I’m generally the only one that has access to the router. There’s another admin, but he generally doesn’t touch it and we’re a small enough company (2 of us network guys) that he would tell me if he had changed anything. I can’t imagine that it was malicious either, as that seems sort of an easy thing to change when there’s so much other stuff that could’ve been done.
So, my question to you dear reader is: Have you ever had this happen before? If so, any suggestions as to what the cause may have been?
