A network device includes multiple interconnected network chips where the packet processing functionality is distributed between ingress and egress pipelines. TCP MSS clamping can be implemented in the egress pipeline. Processing in the egress pipeline can identify the presence of a TCP MSS value in the packet. The egress pipeline can compare the packet TCP MSS value with a user configured TCP MSS value. The egress pipeline can replace the packet TCP MSS value with the user configured TCP MSS value if the former is greater than the latter, and recompute a checksum. The packet with the replaced TCP MSS value and replaced checksum is then forwarded from the switch toward its eventual destination.