Weird DNS entries in Mikrotik DNS cache

RouterOS General
1

Hi,

This may not be a Mikrotik specific issue, but our company uses many Mikrotik routers to set up site to site VPN’s between all our locations.

I noticed at a few sites that their local DNS cache in the Mikrotik has many entries for gibberish names such as “zkhkjsdfgiuseieergmn.ourcompany.local”.

Has anyone encountered this before?

Thanks

2

Does the cache contain a ip to these names?

3

I believe this is done by iOS devices as an attempt to detect captive portals. The entries should be a negative cached response (0.0.0.0).