3Com Switch 7750 Configuration Guide

Troubleshooting DNS Configuration 835
Troubleshooting DNS
Configuration
Symptom
Dynamic DNS resolution is enabled, but the user cannot get the correct IP address
from a domain name.
Analysis
DNS client needs to be used in conjunction with the DNS server to get the correct
IP address through domain name resolution.
Solution
■ Use the display dns dynamic-host command to check if the specified domain
name is in the cache.
■ If the specified domain name is in the cache, but the IP address is wrong,
ensure that the DNS Client has the correct IP address of the DNS Server.
■ If the specified domain name is not in the cache, ensure that dynamic DNS
resolution is enabled, the DNS Client can normally communicate with the DNS
Server, and the DNS Server works normally.
■ Check the DNS mapping list is correct on the DNS Server.
Table 658 Display and maintain DNS
Operation Command Description
Display static DNS list
information
display ip host You can execute the display
command in any view.
Display DNS server
information
display dns server
[ dynamic ]
Display DNS suffix list
information
display dns domain
Display dynamic DNS cache
information
display dns dynamic-host
Clear the dynamic DNS cache. reset dns dynamic-host Execute the reset command
in user view.