kaze on 30 Jul 2004 06:08:04 -0000 |
Have fine long working BIND servers; have fine long working domain which sends and receives email - referred to below as example.com. Recently needed to rush add another domain to host their email (and DNS). Many annoying and weird things happening with email to and from this new (temporarily) hosted domain, one being _some_ servers sending to it get error "451 example.com: Name server timeout". This is the most useful thing I think I found so far: http://www.ntmail.co.uk/support/user_groups/discuss/message.htm?ID=274 Yes, the reverse lookup for hostedexample.com does not match as hostedexample.com basically CNAMEs to example.com, which in tern has a valid reverse lookup. (Hope this is not to dense due to the late night post.) Question: I know many mailserver do reverse lookups on incoming email to thwart spam, but do they also do it as part of the outgoing mail DNS lookup? Below are the bulks of the example.com.zone and hostedexample.com.zone files. (Just removed higher MX value records and some misc www sites.) (I can send the real zone files off-list, just don't want them on the archive forever...) (Note also that the IPs are while they look strange are right as Cisco NAT NATs them to real routable IPs.) Question: Is there a better way I should structure my DNS to smooth everything out? For example would I be better server to have hostedexample.com's MX be email.example.com. instead of email.hostedexample.com.? Should I just dedicate an additional IP address on the mail server for email.hostedexample.com. so it can have it's own reverse lookup and be totally separate? The reason I did it this way was to try to avoid having hostedexample.com's email's headers show example.com. - Zake [root@ns3 named]# cat example.com.zone $TTL 86400 @ IN SOA ns3.example.com. dnsadmin.example.com. ( 2004072201 ; serial 28800 ; refresh 7200 ; retry 604800 ; expire 86400 ; ttl ) IN NS ns1.example.com. IN NS ns2.example.com. IN NS ns3.example.com. @ IN MX 10 email.example.com. @ IN A 10.1.1.51 email IN A 10.1.1.53 ns1 IN A 10.10.10.211 ns2 IN A 10.10.10.212 ns3 IN A 10.10.10.213 www IN CNAME example.com. ftp IN CNAME example.com. smtp IN CNAME email.example.com. pop IN CNAME email.example.com. imap IN CNAME email.example.com. webmail IN CNAME email.example.com. [root@ns3 named]# cat hostedexample.com.zone $TTL 86400 @ IN SOA ns3.example.com. dnsadmin.example.com. ( 2004071901 ; serial 28800 ; refresh 7200 ; retry 604800 ; expire 86400 ; ttl ) IN NS ns1.example.com. IN NS ns2.example.com. IN NS ns3.example.com. @ IN MX 10 email.hostedexample.com. @ IN A 10.1.1.22 email IN A 10.1.1.53 webmail IN CNAME email.hostedexample.com. imap IN CNAME email.hostedexample.com. smtp IN CNAME email.hostedexample.com. www IN CNAME hostedexample.com. ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
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