Before you begin
Create a Network Policy and a Routing
Policy.
About this task
Path MTU Discovery allows the router to monitor the value set
in the MSS option in TCP SYN and SYN-ACK messages, which enables it to reduce the
MSS value below the TCP-MSS thresholds.
Procedure
-
Select Enable Path
MTU Discovery to enable the Extreme Networks router to learn the
maximum packet size that can be sent between two hosts without fragmentation.
-
Select Monitor the MSS Option in TCP SYN and SYN-ACK Messages and
Perform Clamping if the MSS Threshold is Exceeded to monitor the
MSS option in TCP SYN and SYN-ACK messages and, if necessary, reduce the MSS
value as determined by one of the following TCP-MSS thresholds.
- MSS Threshold for All TCP Connections: Set the
TCP-MSS threshold for all TCP connections passing through the device. If
you do not enter a threshold value, TCP-MSS clamping uses Path MTU (40
bytes) for the IP and TCP headers.
- MSS Threshold for TCP Connections Through the VPN
Tunnel: Set the TCP-MSS threshold for TCP connections
that pass through a Layer 3 VPN tunnel. If you do not enter a threshold
value, the device uses the value set for the MSS threshold for all TCP
connections.
What to do next
Continue configuring the network policy.
