~3 min read • Updated Mar 1, 2026
1. named Is Running but No One Can Query It
This is the most common DNS issue: named is active, but external DNS queries fail.
Step 1: Check if named is listening on all IPs
netstat -lnp | grep named
Or for IPv6:
ss -lnp | grep :53
You should see something like:
tcp LISTEN 0 128 0.0.0.0:53 0.0.0.0:* users:(("named",pid=1234))
udp UNCONN 0 0 0.0.0.0:53 0.0.0.0:* users:(("named",pid=1234))
If you only see 127.0.0.1:53 or ::1:53 → named is listening only on localhost.
---Step 2: Fix /etc/named.conf
These lines should NOT exist (or must be commented):
listen-on port 53 { 127.0.0.1; };
listen-on-v6 port 53 { ::1; };
allow-query { localhost; };
Replace with:
listen-on port 53 { any; };
listen-on-v6 port 53 { any; };
allow-query { any; };
allow-recursion { localhost; localnets; };
Restart named:
systemctl restart named
Step 3: Check firewall (port 53 TCP + UDP)
Test from inside the server:
dig google.com @127.0.0.1
If this works but external queries fail → firewall is blocking port 53.
Temporarily disable firewall for testing:
firewalld:
systemctl stop firewalld
iptables:
service iptables stop
CSF:
csf -x
If DNS works after disabling firewall → open port 53:
firewall-cmd --permanent --add-port=53/tcp
firewall-cmd --permanent --add-port=53/udp
firewall-cmd --reload
Step 4: Test from outside
Best tool:
https://www.intodns.com
Or manual test:
dig domain.com @YOUR_SERVER_IP
2. www.domain.com Does Not Work but domain.com Works
This is almost always a DNS propagation issue.
Fix:
- Wait 4–24 hours
- Before major IP changes, reduce TTL to 300–600 seconds
- Check global propagation:
https://www.whatsmydns.net
3. sub.domain.com Does Not Work but domain.com/sub Works
Checklist:
- Does an A record exist for the subdomain?
- Test from inside the server:
dig sub.domain.com @127.0.0.1
- If it does not resolve → named or task.queue is not working
- If it resolves but the website does not load:
Check VirtualHost:
- DNS IP must match the VirtualHost IP in Apache/Nginx
- DocumentRoot must be correct (Sub-Domains Setup → Document Root Override)
If using external DNS:
Add the A record manually in the external DNS provider.
---4. Check resolv.conf and Local DNS Servers
If the server itself cannot resolve domains, check:
/etc/resolv.conf
Correct example:
nameserver 8.8.8.8
nameserver 8.8.4.4
Test:
dig google.com @8.8.8.8
5. Why Do I See “Apache is functioning normally” or “This IP is shared”?
Main reasons:
- The domain resolves to the wrong IP
- No VirtualHost exists for the domain
Quick checks:
Check DNS IP:
dig domain.com
Check DirectAdmin IP assignment:
Admin Level → Show All Users → Domain → Assigned IP
If they do not match → fix the A record or wait for propagation.
Rebuild webserver configs:
cd /usr/local/directadmin/custombuild
./build rewrite_confs
Written & researched by Dr. Shahin Siami