MTU
Maximum Transmission Unit
The largest packet size a network link can carry without fragmentation.
The maximum transmission unit is the largest packet size a network link will carry without fragmenting it into smaller pieces. Mismatched MTU values along a path can cause fragmentation or dropped packets, which degrades performance and can break tunneled or encrypted traffic such as VPNs. Attackers have also abused fragmentation to evade inspection devices that fail to reassemble packets correctly. Tuning MTU and allowing path discovery helps maintain both performance and reliable security inspection.
Looking MTU up is step one. Getting tested on it is step two.
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