Comment 9 for bug 1294085

I use Fuel Master node without internet access (It's normal configuration, internet access for Fuel Master node is not necessarily).
Fuel Master(10.20.0.2) is specified on nodes as nameserver, but Fuel Master node without internet access!!! That is why instances don't have DNS resolution.

In instance:

ubuntu@test:~$ cat /etc/resolv.conf
nameserver 10.0.0.3
search novalocal

ubuntu@test:~$ ping ya.ru
ping: unknown host ya.ru

ubuntu@test:~$ ping -c 3 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_req=1 ttl=47 time=37.2 ms
64 bytes from 8.8.8.8: icmp_req=2 ttl=47 time=39.1 ms
64 bytes from 8.8.8.8: icmp_req=3 ttl=47 time=39.0 ms
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 37.208/38.476/39.167/0.912 ms

In compute:
[root@node-7 ~]# tcpdump -i br100 -p icmp or -p udp dst port 53 or src port 53
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on br100, link-type EN10MB (Ethernet), capture size 65535 bytes
16:23:55.339663 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:24:55.399246 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:25:55.461568 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:26:55.523499 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:27:55.585654 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:28:55.648477 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:29:55.711998 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:30:55.773465 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
16:31:55.835013 IP 10.0.0.4 > 10.0.0.3: ICMP 10.0.0.4 udp port bootpc unreachable, length 346
...