ndd gets and sets selected configuration parameters in some kernel drivers. Currently, ndd only supports the drivers that implement the TCP/IP Internet protocol family. Each driver chooses which parameters to make visible using ndd. Since these parameters are usually tightly coupled to the implementation, they are likely to change from release to release. Some parameters may be read-only.
The tcp/ip abort interval timeout in Solaris 2.x is too short and some programs (like sendmail) sometimes time out and die if the response is too slow. To lengthen this time out period:
/usr/sbin/ndd -set /dev/tcp tcp_ip_abort_interval 1200000 Units are microseconds, so that's 20 minutes. Default is 2 minutes. It may also help to switch of path mtu discovery: /usr/sbin/ndd -set /dev/ip ip_path_mtu_discovery 0
% ndd /dev/udp udp_do_checksum 1