Troubleshooting Dns Configuration - 3Com MSR 50 Series Configuration Manual

618 C 38: DNS C
HAPTER
Troubleshooting DNS
Configuration
ONFIGURATION
# Enable the domain name resolution function.
<DeviceB> system-view
[DeviceB] dns resolve
# Specify the DNS server 2.1.1.2.
[DeviceB] dns server 2.1.1.2
4 Configuration verification
# Execute the ping host.com command on Device B to verify that the host can be
pinged after the host's IP address 3.1.1.1 is resolved.
[DeviceB] ping host.com
Trying DNS resolve, press CTRL_C to break
Trying DNS server (2.1.1.2)
PING host.com (3.1.1.1):
56 data bytes, press CTRL_C to break
Reply from 3.1.1.1: bytes=56 Sequence=1 ttl=255 time=3 ms
Reply from 3.1.1.1: bytes=56 Sequence=2 ttl=255 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=3 ttl=255 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=4 ttl=255 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=5 ttl=255 time=1 ms
--- host.com ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 1/1/3 ms
Symptom
After enabling the dynamic domain name resolution, the user cannot get the
correct IP address.
Solution
Use the display dns dynamic-host command to check that the specified
■
domain name is in the cache.
If there is no defined domain name, check that dynamic domain name
■
resolution is enabled and the DNS client can communicate with the DNS server.
If the specified domain name is in the cache, but the IP address is incorrect,
■
check that the DNS client has the correct IP address of the DNS server.
Check the mapping between the domain name and IP address is correct on the
■
DNS server.