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| 6.2 |  | Troubleshooting Transport Layer Issues on the Router |
| 6.2.5 |  | Gathering information on NAT configuration and operation |

show commands
There are two commands in the show ip nat group of commands. The show ip nat statistics command is used to display statistics on static and dynamic translations on the router, as shown in Figure .

The show ip nat translations command displays the NAT table currently in operation on the router, listing both static and dynamic NAT entries.

The show ip nat translations command also has the optional keywords icmp, pptp, tcp and udp, which allow the network engineer to limit the type of entries displayed. The network administrator can also use the verbose keyword to display additional information about the entries in the table.

debug commands
There is a range of debug commands available for reporting on NAT traffic. A commonly used command is debug ip nat. This command can also have the information displayed limited to events for specific protocols and processes using the keywords h323, port, pptp, route, skinny, and detailed.

Note that the debug command can also use a standard access list to limit the information being displayed by the debug process to traffic matching the permit statements in the ACL.

clear commands
When debugging NAT problems, it can be useful to reset NAT statistics or to clear the NAT table of any dynamic entries. Use the command clear ip nat statistics to reset the NAT traffic statistics counters. Use the command clear ip nat translations * to clear dynamic entries from the NAT table.

Other keywords can be used when clearing the NAT table. The forced keyword clears all IP NAT translations even if they are currently in use. The inside keyword removes all inside addresses and ports from the table, while the outside keyword removes all outside addresses and ports. Using the tcp keyword only removes TCP-related entries. Using the udp keyword only removes UDP-related NAT entries.