Azure VPN MTU setting

Question

_{Monday, March 25, 2019 2:25 PM}

Hi ,

What is the default value of Azure Site-to-Site VPN gateway? 

Is this configurable ? where can I change this value? 

Please help. 

Regards

Thahif

All replies (5)

_{Tuesday, March 26, 2019 4:19 AM ✅Answered}

It is not configurable in Azure end. You need to set the MTU value as 1350 bytes at On-Premises end, in this case Palo Alto. 

Regards, 

Msrini

_{Monday, March 25, 2019 3:52 PM}

Hi Mohammad, 

You cannot change MTU values in Azure VPN gateway. The recommended MSS value to be set on your VPN gateway is 1350. 

Regards, 

Msrini

_{Monday, March 25, 2019 7:34 PM}

MSS Value.. Do you mean on the Azure side? The opposite side of the VPN is a Palo Alto firewall. Should I set the MTU to 1350 along with an adjust TCP MSS of 40?

_{Thursday, March 28, 2019 11:47 AM}

Hi, 

Do you have any update on this issue?

Please 'Mark as answer' if any of the replies helped, so that others in the community who are looking for similar question, can benefit from it.

Regards, 

Msrini

_{Wednesday, April 3, 2019 10:13 AM}

Thanks Msrini, we have matched the MTU value.