crypto ipsec minimal-pmtu

Last Updated : Aug 28, 2026 |
Sets the minimal PMTU value which can be applied to an SA when the Branch Gateway participates in Path MTU Discovery (PMTUD) for the tunnel pertaining to that SA. Use no crypto ipsec minimal-pmtu to restore the minimal PMTU to the default value of
Prolog information
Metadata
Keywords:

Syntax

[no] crypto ipsec minimal-pmtu bytes

Parameters

Parameter
Description
Possible Values
Default Value
bytes
The length of the minimum PMTU
68-1400
300

User level

read-write

Context

interface:FastEthernet (L2, L2-L3, PPP L2, PPP L2-L3), VLAN (L2, L2-L3), Dialer (L2, L2-L3)

Example

To set the minimal PMTU value to 128:
Gxxx-001(if:fastEthernet )# crypto ipsec minimal-pmtu 128