Overvalidation

Updated on Saturday, July 18, 2020

Overvalidation is unhelpful error checking, usually caused by an over-zealous engineer with insufficient domain knowledge. My blood pressure has suffered from two cases of overvalidation this week.

I bought a new NAS — the Linksys NAS200 to set up RAID 1 with a couple of 1TB drives.

I was delighted to discover that the NAS could send email when it detects a problem or starts running out of disk space. Except it couldn't because someone decided that an email server could live at port 25, or at port 1024 or higher.

My ISP blocks port 25 - maybe to cut back on bot spam, maybe because their support staff are bored and lonely. This is far from unique and it's common for email providers to offer an alternative port. Which is almost always port 587. I tried to put a bug report into Linksys but their support pages effectively said "dude, you paid $89 for this box, go talk to other losers on some forum".

Linksys NAS Email Alert Fail

The NAS problem can be solved by redirecting a port on my router. I haven't figured out how to deal with Technorati yet. After spending seemingly months moving their datacenter they've evidently done some work on their blog claim process. I created a new blog yesterday (Webcam Updates, to remove some clutter from the main Catfood Blog) and went over to Technorati to claim it.

When you enter a URL like "http://www.site.com/blog" it's automatically changed to "http://site.com/blog". Which is a different URL. I 301 redirect any "catfood.net" url to "www.catfood.net" to prevent getting dinged by Google for duplicate content. Technorati's claim process fails if there's a 301 redirect.

Technorati Blog Claim Fail

I guess I could remove the redirect, complete the claim and then hope that I can put the redirect back without breaking Technorati. Possibly when my blood pressure is back to normal.

Please, by all means do some validation – "giraffe" is most certainly not a valid TCP/IP port – but don't overvalidate, and don't assume that your mail server port or preferred URL convention is some kind of universal constant.

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(Published to the Fediverse as: Overvalidation #etc #cisco Overvalidation: when an engineer doesn't know what they don't know. )

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