A knowledge of navigating in tmsh is suggested before using the DNAT utility. For
detailed information about navigating in tmsh, see the Traffic Management Shell
(tmsh) Reference Guide.
Deterministic NATs can reduce total log file size but require use of the DNAT
utility (available in tmsh) to decipher the mapping. With the DNAT utility, you can
calculate forward and reverse source address and port mapping of an LSN pool using
deterministic mode based on the state stored in the specified TMM log file.
Use an SSH tool to access the BIG-IP system from the
At the command line, type: tmsh.
This starts tmsh in interactive shell mode and
displays the prompt: (tmos)#.
To show a list of translation address/port pairs used for a subscriber at
10.0.0.1:4321 connecting to 188.8.131.52:80, using the deterministic NAT states
contained in /var/log/ltm, type the command: run
util dnat --file /var/log/ltm --client_addr 10.0.0.1 --client_port 4321
--server_addr 184.108.40.206 --action forward
Replace these example addresses with your actual client and server.
This displays a list of the address/port pairs.
To calculate a reverse mapping back to the subscriber address for the
connection between 220.127.116.11:5678 and 18.104.22.168:80, using the DNAT
states contained in /var/log/ltm.1, type the command:
run util dnat --file /var/log/ltm.1 --server_addr 22.214.171.124
--client_addr 126.96.36.199 --client_port 5678 --action
This displays the reverse mapping.
For more information about the DNAT utility, type the command: help
util dnat at the tmsh prompt.
The help file for the DNAT utility is displayed.
You now have the basic details for deciphering deterministic log files using the
DNAT utility in tmsh.