Dns
 

having problem in DNS/client..........? .
DNS working properly, can resolve names to ip. but when a client ping to another host by name icmp response takes to time but not getting "request time out", but same host ping to another one by ip no delay, there isn't any firewall between clients to clients or clients to server.

Any hint ?

Your question has confused me. What, exactly happens, in each of the ping situations?

I think they said that pinging by name causes a delay before getting back a response but pinging by IP returns an immediate response.

Pinging by name can be delayed if the DNS server that hold the record for the host is not your primary one. The client has to check with every DNS server in the order listed in /etc/resolv.conf to find the host.

Actually, it will only check with one DNS server from /etc/resolv.conf. It is then up to the heirarchical nature of DNS to return the proper record for the host.