3Com 4210G Series, Configuration Manual, Page: 280 / 1133

10-10
# Specify the DNS server 2.1.1.2.
[SwitchB] dns server 2.1.1.2
4) Configuration verification
# Execute the
ping host.com
command on Switch B to verify that the communication between the
Switch and the host is normal and that the corresponding destination IP address is 3.1.1.1.
[SwitchB] 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=126 time=3 ms
Reply from 3.1.1.1: bytes=56 Sequence=2 ttl=126 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=3 ttl=126 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=4 ttl=126 time=1 ms
Reply from 3.1.1.1: bytes=56 Sequence=5 ttl=126 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
Troubleshooting DNS Configuration
Symptom
After enabling the dynamic domain name resolution, the user cannot get the correct IP address.
Solution
z
Use the
display dns dynamic-host
command to verify that the specified domain name is in the
cache.
z
If the specified domain name does not exist, check that dynamic domain name resolution is
enabled and the DNS client can communicate with the DNS server.
z
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.
z
Verify the mapping between the domain name and IP address is correct on the DNS server.