Could not authenticate you from Ldapmain

I have on perm git lab
When I bring down only 1 of my for domains controllers it will not longer sign in
The other three do not have this issue

I can test this by unpluging nic and replug it in

the host is not pointing to this dc its point to another dc

the eroro I get is Could not authenticate you from Ldapmain because "No route to host - connect