Worked example
A 1500-byte link carrying an encapsulation with 60 bytes of overhead leaves a 1440-byte effective MTU.
Base Configuration
Standard Ethernet is 1500. Jumbo frames typically 9000+.
MTU & MSS Calculator
Determine the optimal MTU and TCP MSS values for your network. Account for encapsulation overhead from tunnels and various transport protocols to prevent fragmentation.
How to use MTU Calculator
Select each encapsulation layer to calculate effective packet MTU and recommended TCP MSS across a tunnel path.
Common mistake
Ignoring the outer IP version, NAT-T, or stacked VLAN headers can underestimate real overhead.