I've recently been noticing some "odd" behavior from my ISP's DNS server when a domain does not exist. It's been causing me some problems and I was wondering if these DNS servers are actually conforming to the standard.
It started with them adding the feature that if you request an incorrect domain, it directs you to a search page that they run. I guess this is useful for some people when web browsing, but it borks things up for other applications particularly if the search server has some other open ports such as SMTP.
To get round this, I changed preferences with my ISP to turn this feature off. Now my ISP's DNS does something lot stranger... When a domain can not be found, it returns MY own IP as the A name for that non-existant domain. So now if I click a link which no-longer exists, it bounces me to my own home page (run through the same Internet connection).
I'm trying to understand why being bounced to my own IP would ever be useful. More to the point, is this the standard or are they breaking the standard for some purpose best known to themselves?