Idiot Moment - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: January 29, 2017, 08:38:10 am
content: I feelsostupid.I've just spent the last three hours trying to track down a network problem on one of my Cisco switches. I updated some IP and DNS settings, then added new server details for some stratum one time servers. Absolutely nothing I did would allow the switch to sync with any of the time servers.Then I found it... I had neglected to input the IP address of the gateway in the switch config (which Ithoughtassumed was already in there).I feel so small right about now and I should bloody know better! (I blame the wine.)

author: andtfoot
author_rank: Unknown
timestamp: January 29, 2017, 08:52:03 am
content: I'll admit that I've had similar moments with network stuff; like accidentally putting a comma instead of a dot for one of the subnet mask octets, or putting in a number higher than 255.Can't say I was impressed with the error handling on the inputs fields, but I was less impressed with myself for not double checking...

author: 1xrtt
author_rank: Regular Contributor
timestamp: January 29, 2017, 07:15:56 pm
content: During my years in telecom industry, one thing that I disliked in Cisco routers was that the config file never displays the parameters with default values. So you *must* knew what were the defaults. While, for something like a default route or gateway, it may seem obvious, for some other parameters, the subtle differences can give strong headaches.On a Christmas eve, years ago, I got a call from an account manager. One of our customers (a carrier) was trying to establish an ATM E3 link between our equipment and a Cisco router for one of their customers (a government agency). Because of the high profile of the end customer and because *I* was the one who, a few weeks earlier, tested and validated that scenario, the tone of the call had a strong component of "get your a*s there and fix whatever you f*ed up" (none of these words were really used, but you got the idea).So, one hour later, I showed up at that government agency and, after looooong minutes of psychological consulting, giving my ears to all sorts of recrimination, claims of urgency, anger and bitterness (they were trying to make that link work for the past two days), I finally sat at our equipment console and quickly saw that there were a lot of cell errors on the interface. After some more minutes of fiddling around, comparing the configuration done at the equipment with my lab notes, and confirming it was exactly the same as I tested, I decide to try changing the cell scrambling parameter, from "disable" to "enable",just to give it a try, and voila! - It worked!While people around was giving me the look of "I told you so, you f*ed the configuration", I decided to check the Cisco configuration, both from the tests and customer's environment and they also were the same, but as none showed the default parameters, it only added to confusion. However, when comparing the IOS versions, the customer's router had a newer one than the lab. I pointed that to them and asked to do a new test. I returned my configuration of the cell scrambling to disable, while they changed the Cisco to "no payload scrambler" and as I expected, it worked.So, people wasted two days and had a lot of misplaced anger, because of a simple parameter had its default value changed between versions and no one got aware of that.Before being accused, It's not my intention to flame Cisco here, I'm sure that change was documented somewhere (I actually googled it, to refresh my memory), I was spoiled because I could display my equipment's configuration and see all the parameters, the ones I changed and the ones which still have their defaults, and not having this same ability on Cisco really annoyed me, at that time.