To troubleshoot the failure, perform the following operations:
1. View the traffic statistics on related interfaces to check whether traffic arrives at the interfaces (statistics enabling may be required for subinterfaces).
2. Run the Disp access-user xxx verbose command to check whether the user traffic increases. This aims to check whether users transmit traffic and whether users are bound with NAT correctly.
3. Enable statistics in the traffic policy and run the disp traffic policy statistics ucl inbound command to check whether forwarded packets are counted and whether traffic distribution succeeds.
4. Run the Disp nat statistics received/discard command to check whether any traffic enters the CGN board. If traffic is discarded on the CGN board, check causes for packet discarding according to the keyword discard.5. Run the disp nat session table and disp nat user-info commands to check related table entries.