  Configuring IP MTU (segments)? 
 The Question is:
 
TCP/IP V 4.0
How to adjust TCP-Segment (MMS) size? Our system tries to break down TCP
 segments into IP packets with a maximum of 512 bytes of data. 'ucx&gt; set proto
 tcp /mtu ' has no effect (MTU-Size is 1500!).
 
 
 The Answer is:
 
  Please move to TCP/IP Services V4.2, or (better) please move to
  OpenVMS VAX V7.2 or later with TCP/IP Services V5.1 and later,
  and with appropriate ECO kits applied.
 
  On releases as old as V4.2, you will want to use the logical name
  UCX$FTP_WNDSIZ to control the FTP window size, if that is the
  protocol of interest.
 
  With V4.x series releases and YOU MUST HAVE THE CURRENT ECO KITS
  INSTALLED, use the commands:
 
    SET CONF COMM/TYPE=DEFAULT
    SET CONF COMM/TYPE=FDDI
    SET CONF COMM/TYPE=ETHER
 
  and
 
    SET PROTOCOL TCP /MTU_SEGMENT_SIZE
 
  IPv6 eliminates much of the "fun" involved here.
 
