Cisco Cisco IOS Software Release 12.2(14)S
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TCP MSS Adjustment
The TCP MSS Adjustment feature enables the configuration of the maximum segment size (MSS) for
transient packets that traverse a router, specifically TCP segments in the SYN bit set, when Point to Point
Protocol over Ethernet (PPPoE) is being used in the network. PPPoE truncates the Ethernet maximum
transmission unit (MTU) 1492, and if the effective MTU on the hosts (PCs) is not changed, the router in
between the host and the server can terminate the TCP sessions. The ip tcp adjust-mss command
specifies the MSS value on the intermediate router of the SYN packets to avoid truncation.
transient packets that traverse a router, specifically TCP segments in the SYN bit set, when Point to Point
Protocol over Ethernet (PPPoE) is being used in the network. PPPoE truncates the Ethernet maximum
transmission unit (MTU) 1492, and if the effective MTU on the hosts (PCs) is not changed, the router in
between the host and the server can terminate the TCP sessions. The ip tcp adjust-mss command
specifies the MSS value on the intermediate router of the SYN packets to avoid truncation.
History for the TCP MSS Adjustment Feature
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Contents
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Release
Modification
12.2(4)T
This feature was introduced.
12.2(8)T
The command that was introduced by this feature was changed from ip
adjust-mss to ip tcp adjust-mss.
adjust-mss to ip tcp adjust-mss.
12.2(27)SBA
This feature was integrated into Cisco IOS Release 12.2(27)SBA.