Jul 25, 2015 · MTU value for said protocols is set by VPN administrators approximately, according to the minimum MTU size among all VPN users. OpenVPN, the most popular VPN solution, has chosen the other way.
When I used the default settings, configured by the SDM, it set the tunnel MTU to 1420. With that default setting I was able to bring up the tunnel, but simple tcp services would not Find A Community Specify MTU for an IPSec Tunnel | Fortinet Technical Sep 20, 2016 MTU - Palo Alto Networks
Jumbo Frames with VPN | AnandTech Forums: Technology
Understanding MTU and MRU Configuration for PPP MX Series. PPP MTU and MRU for PPPoE Subscribers, PPP MTU and MRU for Tunneled Subscribers on LNS
MTU Tuning for L2TP - Cisco
Network maximum transmission unit (MTU) for your EC2 VPN connections and traffic sent over an internet gateway are limited to 1500 MTU. If packets are over 1500 bytes, they are fragmented, or they are dropped if the Don't Fragment flag is set in the IP header. What is the Max MTU for PPTP VPN ? :: SG FAQ The Maximum MTU for PPTP tunneling VPN using Ethernet in Windows 9x/ME is 1462. In Windows XP/2k/2k3, it seems to be limited to 1400 by default. See this Microsoft article for changing the Max MTU value in Windows XP/2k/2k3: MS KB 826159 Recommended TCP/IP settings for WAN links with a MTU size