Assigned numbers.

Christopher R. Hertel crh at NTS.Umn.EDU
Tue Sep 29 16:59:51 GMT 1998

I've been poking around a bit and have a few questions.

  Port 42:   It appears as though this is being used for WINS replication. 
             Any truth to the rumor?

  name             42/tcp    Host Name Server
  name             42/udp    Host Name Server
  nameserver       42/tcp    Host Name Server
  nameserver       42/udp    Host Name Server

  Port 135:  This is listed as a DCE/RPC termination port.  Is this being
             used by the NT DCE/RPC stuff at all?

  epmap           135/tcp    DCE endpoint resolution
  epmap           135/udp    DCE endpoint resolution
  #                          Joe Pato <pato at>

  Ports 137, These are assigned for both tcp & udp.  It appears, however,
        138, that they are not used that way.  In nmbd.c:open_sockets(),
      & 139: both the NetBIOS Name Server port and the Datagram port are
             opened as SOCK_DGRAM.  RFC1002 talks about using both udp
             and tcp for name resolution.  Is this done?

             The RFC says (in section that the truncation flag
                      "Set if this message was truncated because the
                       datagram carrying it would be greater than
                       576 bytes in length.  Use TCP to get the
                       information from the NetBIOS Name Server."

Going through the latest port assigments at
I notice several of entries by Microsoft.  I don't know how many of these
are new.  Comments?

Oh, BTW...  In nameserv.h it is written:  

#define MAX_DGRAM_SIZE (576) /* tcp/ip datagram limit is 576 bytes */

Shouldn't we say "udp/ip"?

Yours pedantically,

Chris -)-----

Christopher R. Hertel -)-----                   University of Minnesota
crh at              Networking and Telecommunications Services

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