FortiGate
FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
Hsharma
Staff
Staff
Article Id 331493
Description This article describes the impact of Changing the MTU value of an aggregate interface.
Scope FortiGate.
Solution

If there are two or three interfaces are part of the aggregate interface, so changing the MTU value of the aggregate interface will also change the MTU size of all physical interfaces. For Example:

 

Port3 and port4 are part of the aggregate interface:


image1.jpg

 

 

Initially, MTU size of port 3 and port 4 is set as a default value of 1500 as shown in the screenshot. To check the MTU size use the below command:

 

diag netlink interface list <NIC name>

 

image2.jpg

 

Changing MTU size of Aggregate interface named as 'Test' to value 1300.

 

image3.jpg

 

After changing the MTU value of the aggregate interface, the Port3 and port4 MTU values will also change.

 

image4.jpg

 

Related article:

Technical Tip: Finding the MTU of the FortiGate interface