[bit.listserv.ibmtcp-l] smtp and host tables

KF0S@CMUCCVMA.BITNET (Kamran Farshchi) (02/01/90)

Folks,
     We are running FAL 1.2.1 here at CMU.  A few days ago we had problem
with one of our CP owned disk which crashed the machine.  The machine
came up without the disk until the problem was fixed and the disk was
attached to the system.

     Meanwhile FAL was running.  Our host tables happened to be on the
bad disk!  The SMTP mail service rejected all messages destined for
".cmu.edu" domain with unknown host reason.  This continued for a few hours
until someone noticed it!

     I suggest that FAL should exit in cases such as these to prevent
some of these problems.  I have added code to our system to check
for these to make sure no mail messages is lost (at least for smtp).

Thanks
postmaster@cmuccvma

RUBIN@YKTVMX.BITNET (Bill Rubin) (02/01/90)

There is no requirement to have host tables in order to run SMTP.  Most
people would prefer that we use the name server to query host names and
not bother going to the host tables at all.  In fact, in SMTP/MX (to be
included on the upcoming 1.2.2 PTF tape) this is exactly what we do.
If you're using the name server and we cannot get a response due to the
remote name server being down, then we requeue the request for later
and attempt to resolve the name at that time.  We will no longer use
the host tables unless it is the only means of resolution on your
system.

If your system has a requirement for the host tables, then it might not
be a bad idea to put a STATE for HOSTS SITEINFO into TCPIP's startup
exec and exit if it does not exist.

Bill Rubin
IBM TJ Watson Research