Symptom:
When a client uses NFS to connect to the V3 NAS, the file fails to be locked.
Analysis:
Capture packets and analyze the captured packets. It is found that V3 receives an ICMP packet when an exception occurs.
3 10 Destination host administratively prohibited
The V3 NLM uses the asynchronous mode. That is, the V3 rejects the lock request (NLM_BLOCKED) from the client, and then actively connects to port 111 of the client to inform the client that the lock is available. Therefore, the port 111 of the client must be open.
Solution:
Enable the firewall on port 111 on the client.
iptables -A input -p tcp --dport 111 -j ACCEPT
Run the following command to make the configuration persistent:
service iptables save
or
iptables-save > /etc/sysconfig/iptables
Summary:
You can learn the types of ICMP packets to quickly locate firewall faults.
