How to clear Don't Fragment (DF) bit

I'm feeling the heat now! I've edited my post to correct the MSS/MTU 'order'. As stated here: http://en.wikipedia.org/wiki/Transmission_Control_ProtocolMaximum_segment_size:

 

 

"...typically the MSS is announced by each side using the MSS option when the TCP connection is established, in which case it is derived from the maximum transmission unit (MTU) size of the data link layer of the networks to which the sender and receiver are directly attached..."

 

 

Regarding the Ethernet standard of a minimum MTU of 1500 I would generally agree with you but in this case, considering the local significance, the fact lower MTUs are very likely to exist outside of the local network, the fact PMTUD effectively does the same thing at layer three and the lack of any ability to manually modify the IP MSS (which is available on most hosts) on the BIG-IP I would make an exception. I've done this in many live and busy environments without ever facing an issue.