Weird error, and probably related to me being fairly unused to Linux. I've got two systems, both RHEL 7. I've got one setup as a BIND DNS server, and that appears to be working fine. I did a minimal install for the other one.

The DNS server IP is 192.168.0.6
The server with the issue is 192.168.0.2
Gateway is 192.168.0.1. Network mask is 24. The gateway also happens to be a DNS server.

From 0.2,I can ping 0.6 just fine. nslookup to the 0.1 server works as well. DNS queries to 0.6 from 0.2 are failing though. I thought perhaps it was an issue with the DNS server I built, so I loaded the telnet client and tried to connect to 0.6 from 0.2 over port 53, and go a "no route to host" error (which is weird, because the ping worked). Not really sure where to go with this and would appreciate some thoughts. Routing table from 0.2 shows as

default route via 192.168.0.1 Dev eth0 proto static metric 100
192.168.0.0/24 Dev eth0 proto kernel scope link sec 192.168.0.2 metric 100

ping uses the icmp protocol.
DNS normally uses udp on port 53, with TCP for large queries eg zone file txfrs.
See /etc/services.

Have you checked the firewall on both systems?

Try running tcpdump on 0.6 http://www.rationallyparanoid.com/articles/tcpdump.html

1 members found this post helpful.

Thanks for the response. I'd actually finished running nmap on both systems a few minutes ago, and the server I was having an issue with didn't see 53 as an open port on the DNS server, although the DNS server did see it on itself. Ran firewall-config and enabled the DNS service, and now it's working like a champ.

ICMP may be turned off in the target system. Some systems do that by default.

http://www.linuxchix.org/content/courses/security/icmp