I'm willing to give the consultant the benefit of the doubt, as I may be lacking some crucial information. But the way you're presenting it, you're perfectly right.
- two of your office's client computers have DNS issues
- DNS is handled by a network server in the office
- the consultant would like to check why
Correct?
Does the consultant have access to said server? If so, has he already checked through logs to see if the clients are attempting to fetch information from it at all, i.e. has he exhausted all server-side options of tracking down this problem?
How do the clients know which DNS server to connect to (DHCP?), and do they need to authenticate against it (ActiveDirectory? Some other directory service?)?
If your user account is involved in authenticating with DNS, that may explain the request.
At the same time, it's an unusual request, and
you're right to be concerned. An admin should have have to ask you your password. They should be able to reproduce it by creating a similar test account of their own.
However, to make things easy, just reset the password to something temporary, give that to him, let him check things, and then set it back to your real password.
Hope that helps