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unexpected MTU value
New Contributor

unexpected MTU value

Hi all,


I've set the 1500 MTU value on both the internal and external interfaces but when I connect the client my virtual adapter on WI-FI interface is set to 1292 MTU value instead of the 1400 as expected.


Firewall in the middle has a 1500 MTU value.


What can be the cause of this unexpected behavior?


Thanks in advance..




Re: unexpected MTU value

Is it happening on all the machines? What is the Client OS?


MTU value sent by the VPN server would be seen in the debuglog, can you please provide a copy of that?

PCS Expert
Pulse Connect Secure Certified Expert
New Contributor

Re: unexpected MTU value

Hi Ray,


clients OS tested are all Win10.

I'll make a snapshot including debuglog.


Thank you,


Frequent Contributor

Re: unexpected MTU value

Article KB21481 explains how MTU is calculated.