MX Reverse lookups

[Mark_Andrews at isc.org]

> I'm sure you all have seen this question asked many times but for some
> reason I cannot put in the right search topic to get an answer I understand.
> 
> I have one server running sendmail and in addition to the primary domain
> piopc.net I have several virtual e-mail domains also. I've been running
> these for some time and everything works fine (operationally). However an
> ISP in my area has just installed something new on their mail servers that
> is blacklisting my domain. I don't think it's from spam I think it's because
> their software does a reverse lookup on mail that comes in and mine is
> failing.
> 
> Below are my zone files and I'm hoping someone can help me with my
> configuration.
> Primary zone file:
> 
> $TTL 86400
> 
> @       IN      SOA     ns1.piopc.net. dnsadmin.piopc.net. (
>                                   20020314002        ; Serial
>                                   8H                         ; Refresh
>                                   2H                         ; Retry
>                                   1W                        ; Expire
>                                   1D)                        ; Minimum
> 
>            NS      ns1.piopc.net.                     ; Primary name server
>            NS      ns2.piopc.net.                     ; Secondary name
> server
>            MX     10 mail.piopc.net.               ; Primary mail server
> 
> localhost                      IN    A                   127.0.0.1
> dev.piopc.net.              IN    A                   207.14.72.35
> ns1.piopc.net.              IN    A                   207.14.72.25
> ns2.piopc.net.              IN    A                   207.14.72.26
> www.piopc.net.           IN    A                   207.14.72.36
> fp.piopc.net                 IN    A                   207.14.72.35
> home.piopc.net.           IN    A                   207.14.72.36
> ftp.piopc.net.               IN    A                   207.14.72.36
> mail.piopc.net.             IN    A                   207.14.72.45
> news.piopc.net.           CNAME                corp.supernews.com.
> pop3.piopc.net.           IN    A                   207.14.72.45
> smtp.piopc.net.            IN    A                   207.14.72.45
> 
> reverse lookup file
> 
> $TTL 86400
> 
> @         IN         SOA       ns1.piopc.net. dnsadmin.piopc.net. (
>                           20010326002          ; Serial
>                           8H                           ; Refresh
>                           2H                           ; Retry
>                           1W                          ; Expire
>                           1D)                          ; Minimum TTL
> 
>             NS         ns1.piopc.net.
>             NS         ns2.piopc.net.
> 
> 25        IN          PTR                  ns1.piopc.net.
> 27        IN          PTR                  ns2.piopc.net.
> 36        IN          PTR                  www.piopc.net.
> 45        IN          PTR                  mail.piopc.net.
> 
> 
> Here is one of the zone files:
> 
> $TTL 86400
> 
> @        IN           SOA         www.branyik.com.  hostmaster.piopc.net.  (
> 
>                            20011115001             ; serial YYYYMMDDXXX
>                            7200                           ; refresh
>                            3600                           ; (1 hour) retry
>                            1728000                     ; (20 days) expire
>                            3600)                          ; (1 hour) minimal
> TTL
> 
> ; Name Servers
> 
>                            IN        NS      ns1.piopc.net.
>                            IN        NS      ns2.piopc.net.
>                            IN        MX     10   mail
> 
> ; CNAME records
> mail.branyik.com.       IN     A        207.14.72.45
> 
> Do I need to put a PTR record in for each virtual domain. Or should I use a
> CNAME to point my MX record to mail.piopc.net (the mail server).
> 
> Thanks for any help you can give me.
> 
> V. Branyik
> 
> 
> 

	Talk to SPRINT about getting the in-addr.arpa address space delegated
	to you.  You only need one PTR for any given address.  Also if you
	don't have a full /24 see RFC 2317 for how to do small delegations.
	
	Mark

; <<>> DiG 9.2.1rc2 <<>> -x 207.14.72.45
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 32366
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;45.72.14.207.in-addr.arpa.	IN	PTR

;; AUTHORITY SECTION:
14.207.in-addr.arpa.	10800	IN	SOA	ns1-auth.sprintlink.net. dns-admin.sprintlink.net. 2002032101 43200 3600 2419200 86400

;; Query time: 306 msec
;; SERVER: ::1#53(::1)
;; WHEN: Wed Apr 10 17:00:33 2002
;; MSG SIZE  rcvd: 112

--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark.Andrews at isc.org