Cisco Cisco IOS Software Release 12.2(27)SBC

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This document explains the the behavior of the mpls mtu command in Cisco IOS Release 12.2(27)SBC, 
12.2(33)SRA, 12.4(11)T, 12.2(33)SXH, and later releases. You cannot set the MPLS MTU value larger 
than the interface MTU value. This eliminates problems, such as dropped packets, data corruption, and 
high CPU rates from occurring when MPLS MTU value settings are larger than interface MTU values. 
Cisco IOS software allows the MPLS MTU value to be higher than the interface MTU value only for 
interfaces that have a default interface MTU value of 1580 or less.

Your Cisco IOS software release may not support all of the features documented in this module. To reach 
links to specific feature documentation in this module and to see a list of the releases in which each feature is 
supported, use the 

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