server1 and server2 are guest VMs in a KVM host machine:
server2.example.com[192.168.4.220] : Client querying server1
[user@server2 ~]$ nslookup server2.example.com 192.168.4.210 ;; connection timed out; no servers could be reached [user@server2 ~]$ ping -c 1 192.168.4.210 PING 192.168.4.210 (192.168.4.210) 56(84) bytes of data. 64 bytes from 192.168.4.210: icmp_seq=1 ttl=64 time=0.385 ms --- 192.168.4.210 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 0.385/0.385/0.385/0.000 ms [user@server2 ~]$ [user@server2 ~]$ nmcli con show eth0 | grep ipv4.dns ipv4.dns: 192.168.4.210, 220.127.116.11 ipv4.dns-search: example.com [user@server2 ~]$
Edit : Ok , now i seem to have fixed the problem but still unable to understand what is the problem. running wireshark shows error : "Code 10 = Communication with Destination Host is Administratively Prohibited)."
Online search showed that its related to firewall and needed to run
service iptables stop;iptables --flush
Thats it, nslookup is working now.but still unable to get my head around the problem since firewall-cmd has replaced iptables and i don't understand what is really going on.