Bizarre limit alert.

Christopher R. Hertel crh at
Tue Feb 25 08:04:23 GMT 2003

I've been testing the SMB Echo message and found a very odd thing.

If I send an echo request message to NT4 SP6 with a payload of 4323 bytes
NT4 responds just fine.  If the payload is 4324 bytes NT4 does not reply.

Of interest, the payload of 4323 bytes generates one ECHO Request and two
continuation messages on the (Ethernet) wire.  The ECHO Request and first
continuation message are 1514 bytes in (total) length.  The last
continuation message is 1498 bytes...16 bytes less than 1514.  Hmmm...

I like weird stuff like this.

Chris -)-----

PS.  W2K doesn't have the same problem.  I can send an ECHO Request with
     a payload as big as 16611 bytes.  Curiously, at 16612 bytes and above
     W2K will reset the connection.  "Connection reset by peer".

Samba Team --     -)-----   Christopher R. Hertel
jCIFS Team --   -)-----   ubiqx development, uninq.
ubiqx Team --     -)-----   crh at
OnLineBook --    -)-----   crh at

More information about the samba-technical mailing list