There DNS server went down and it is take too long to go to next DNS server in the resolv.conf. If the working DNS server is not the first entry in the resolv.conf file, the latency seems to be much greater
Ensure DNS is correctly configured and that name resolution is able to occur to and from the client machine and the domain controllers in a timely manner.
Ensure the /etc/resolv.conf is correct on the client machine.
To test name resolution for a particular on the host, you can use the nslookup command and specify the ip address of each DNS server:
nslookup -q=SRV < _ldap._tcp.dc._msdcs.yourdomain.com > < nameserver IP>
Add the /etc/resolv.conf option timeout:1 setting