Skip to main content
BensonLEI
BensonLEI
New Member
June 24, 2021
Question

GRE tunnel performance SLA

  • June 24, 2021
  • 1 reply
  • 2089 views

Hi, guys,

 

I am using Fortigate 400E, 600E with FortiOS v6.4.2 and V6.4.4. For some reasons, my company perfers GRE tunnel.

 

It is found that the poor performance SLA of the GRE tunnel between two fortigates  ( often some percentage of packet loss often found, while the internet lines are running well - no packet loss ), any advice, thx a lot ?

 

Any article/doc to fine tune the GRE tunnel parameters/attributes ?

 

 

 

 

1 reply

pavankr5
Staff
pavankr5
Staff
January 27, 2025

Hello @BensonLEI 

Once check MTU size is properly configured on both ends of the GRE tunnel. Misconfigured MTU settings can lead to packet loss and performance issues. adjusting the TCP MSS value to prevent fragmentation issues
Understanding PMTU on GRE tunnel and using fragmentation to recover the tunnel traffic
let us know if this helps

Thanks
Pavan


    Terms & ConditionsAccessibility statement