Discussion of ip_pmtu_strategy
----------------------------------
The default value for ip_pmtu_strategy is 1. This allows for PMTU
discovery. Once the issue of this Security Bulletin has been
resolved via patches the ip_pmtu_strategy value of 1 will again be
the preferred setting for most situations.
The ip_pmtu_strategy values of 0 and 3 set the PMTU to a fixed
size for destinations which are not on the local network.
The ip_pmtu_strategy value of 0 sets the PMTU to 576 bytes.
Routers are required to handle packets of at least this size.
The ip_pmtu_strategy value of 3 sets the PMTU to 1500 bytes. This
will generally result in more efficient transmission than the 576
byte PMTU. If it is known that the routers involved can handle a
1500 byte MTU the ip_pmtu_strategy value of 3 is preferred.