3Com Switch 8800 Advanced Software V5 Configuration Guide

Troubleshooting NAT 1003
[Sysname] nat log enable
You must run XLog on the NAT log server or the system log server to view NAT log
information.
Troubleshooting NAT
Symptom 1: Abnormal
Translation of IP
Addresses
Solution: Enable debugging for NAT. Try to locate the problem based on the
debugging display. Use other commands, if necessary, to further identify the
problem. Pay special attention to the translated source address and ensure that
this address is the address that you intend to change to. If not, there may be an
address pool bug. Also ensure a route is available between the destination
network and the address pool segment. Be aware of the possible effects that the
firewall or the ACLs have to NAT, and also note the route configurations.
Symptom 2: Internal
Server Functions
Abnormally
Solution: Check whether the internal server host is properly configured; whether
the router is correctly configured with respect to the internal server parameters,
such as the internal server IP address. It is also possible that the firewall that has
denied external access to the internal network. You can use the display acl
command to verify this.