| Description |
This article describes the behavior of setting TCP-MSS under config system interface.
Network diagram:
|
| Scope | FortiGate. |
| Solution |
Behavior in FortiOS 6.0.x, 6.2.x, 6.4.x and 7.0.0:
The change of TCP-MSS is done only in one direction (only for return traffic).
Example 1:
# config system interface end
The result will be:
- Client -> Server, MSS is unchanged (typically 1460). - Server -> Client, MSS=1300.
Example 2:
# config system interface
The result will be:
- Client -> Server, MSS=1200. - Server -> Client, MSS is unchanged (typically 1460).
Example 3:
# config system interface
The result will be:
- Client -> Server, MSS=1200. - Server -> Client, MSS=1300
Behavior in FortiOS from 7.0.1 and 7.2.x.
The change of TCP-MSS value is done in both directions.
Example 1:
# config system interface end
The result will be:
- Client -> Server, MSS=1300. - Server -> Client, MSS=1300
Example 2:
# config system interface
The result will be:
- Client -> Server, MSS=1200. - Server -> Client, MSS=1200
Example 3:
# config system interface
The result will be:
- Client -> Server, MSS=1200. - Server -> Client, MSS=1200.
Related article: |
