Our new WAN provider recommends setting an MTU on our hosts to avoid fragmentation and issues as there are multiple layers of IPSEC encapsulation going on across the WAN.
I can't find a command to set the MTU on the CSS11500 the way I can on all my other Cisco gear. Hoping someone here can help before I go to the TAC.
you can't change the MTU but you can play with the TCP MSS which is all you should need.
CSS11503-2(config)# flow tcp-mss ?
Integer value(Range: 1-1460)
CSS11503-2(config)# flow tcp-mss