sendmail and bind

[Boex,Matthew W.]

question.  i am seeing some weird things when sending inbound mail from our
smtp server.  first, we have two machines handling our smtp traffic.  both
machines are configured exactly the same, sendmail ( 8.11 ) and dns ( bind
8.1.2.).  each machine is running on HP-UX 11.0.   each machine has its own
copy of bind ( caching ) running locally, with only localhost and the root
hints file in the named.conf.  

our inbound mail is configured to use a mailer definition table.  the
inbound server ( defined in the mailer definition table in sendmail.cf ) is
wch1xi03.cna.com.  the ip address for it is in our host file.  we do have
nsswitch properly configured to check hosts, then dns.    

here is the weird part.  on one machine sch1p312, it there is no delay
sending inbound mail.  the other, sch1p297, has about a 30 sec. delay
sending inbound.  both machines are exactly the same.

here is a inbound test with dns debug on for each machine.  as you can see,
sch1p297 is attempting more lookups than sch1p312.  how can this possibly be
?  also, why doesn't dns fall back on the host file immediately ?

-------------------------------------------------------------------------

sch1p312 ( this test took about 3 secs. to send )

sendmail -d8.8 -vv matthew.boex at cna.com < test

RES_DEBUG not available due to SFIO
dns_getcanonname(cna.com, trymx=1)
dns_getcanonname: trying cna.com. (ANY)
        YES
dns_getcanonname: cna.com
getmxrr([cna.com], droplocalhost=1)
dns_getcanonname(cna.com, trymx=0)
dns_getcanonname: trying cna.com. (ANY)
        YES
dns_getcanonname: cna.com
getmxrr(wch1xi03.cna.com, droplocalhost=1)
getmxrr: res_search(wch1xi03.cna.com) failed (errno=0, h_errno=0)
dns_getcanonname(wch1xi03.cna.com, trymx=0)
dns_getcanonname: trying wch1xi03.cna.com. (ANY)
        YES
dns_getcanonname: wch1xi03.cna.com
matthew.boex at cna.com... Connecting to wch1xi03.cna.com. via XCHANGE...
220 wch1xi03.cna.com InterScan VirusWall NT ESMTP 3.51 (build 1366) ready at
Wed, 24 Oct 2001 12:33:29 -0500
>>> EHLO sch1p312.cna.com
250-wch1xi03.cna.com supports the following ESMTP extensions:
250 SIZE 5242880
>>> MAIL From:<root> SIZE=95
250 <root>: Sender Ok
>>> RCPT To:<matthew.boex at cna.com>
250 <matthew.boex at cna.com>: Recipient Ok
>>> DATA
354 wch1xi03.cna.com: Send data now.  Terminate with "."
>>> .
250 wch1xi03.cna.com: Message accepted for delivery
matthew.boex at cna.com... Sent (wch1xi03.cna.com: Message accepted for
delivery)
Closing connection to wch1xi03.cna.com.
>>> QUIT
221 wch1xi03.cna.com closing connection. Goodbye!

-------------------------------------------------------------------------
sch1p297 ( this test took about 30 secs. to send in )

sendmail -d8.8 -vv matthew.boex at cna.com < test

RES_DEBUG not available due to SFIO
dns_getcanonname(cna.com, trymx=1)
dns_getcanonname: trying cna.com. (ANY)
        YES
dns_getcanonname: trying cna.com. (A)
        NO: errno=0, h_errno=0
dns_getcanonname: trying cna.com. (MX)
        YES
dns_getcanonname: cna.com
getmxrr([cna.com], droplocalhost=1)
dns_getcanonname(cna.com, trymx=0)
dns_getcanonname: trying cna.com. (ANY)
        YES
dns_getcanonname: trying cna.com. (A)
        NO: errno=0, h_errno=0
dns_getcanonname: trying cna.com. (MX)
        YES
dns_getcanonname: cna.com
getmxrr(wch1xi03.cna.com, droplocalhost=1)
getmxrr: res_search(wch1xi03.cna.com) failed (errno=0, h_errno=0)
dns_getcanonname(wch1xi03.cna.com, trymx=0)
dns_getcanonname: trying wch1xi03.cna.com. (ANY)
        YES
dns_getcanonname: wch1xi03.cna.com
matthew.boex at cna.com... Connecting to wch1xi03.cna.com. via XCHANGE...
220 wch1xi03.cna.com InterScan VirusWall NT ESMTP 3.51 (build 1366) ready at
Wed, 24 Oct 2001 12:38:06 -0500
>>> EHLO sch1p297.cna.com
250-wch1xi03.cna.com supports the following ESMTP extensions:
250 SIZE 5242880
>>> MAIL From:<root> SIZE=109
250 <root>: Sender Ok
>>> RCPT To:<matthew.boex at cna.com>
250 <matthew.boex at cna.com>: Recipient Ok
>>> DATA
354 wch1xi03.cna.com: Send data now.  Terminate with "."
>>> .
250 wch1xi03.cna.com: Message accepted for delivery
matthew.boex at cna.com... Sent (wch1xi03.cna.com: Message accepted for
delivery)
Closing connection to wch1xi03.cna.com.
>>> QUIT
221 wch1xi03.cna.com closing connection. Goodbye!



Matthew Boex
Sendmail Group
312.822.3955