Using Path MTU Discovery feature on SonicWall.

Using Path MTU Discovery feature on SonicWall.

Using SonicWall PMTU Discovery feature we can find the MTU size required to access any particular website or IP address on internet. This information can then be used for diagnostics purposes.

Login to SonicWall UTM device.

Go to System | Diagnostics

On Diagnostics page, go to Diagnostic Tools and from the drop-down menu select PMTU discovery.

Then in the blank box in front of “Path MTU Discovery to this host or IP address:”  type the domain name (for example, google.com) or the IP address (for example, 8.8.8.8).

Interface: Select the required WAN interface.

Then click on “Go”.

You will get a pop-up window where you can see the Path MTU.