Scriblings Of A GEEK

Coming back to setting MX records in DNS for mail server

A quick look at the MX records for one of the websites say redhat.com

redhat guys if you find the info here i cannot post pls dunn feel offended and mail me and i will remove it from here :)

C:\WINDOWS\system32>nslookup
Server: Mydns.server
Address: A.B.C.D

> set querytype=MX
> redhat.com
Server: Mydns.server
Address: A.B.C.D

Non-authoritative answer:
redhat.com MX preference = 10, mail exchanger = mx3.redhat.com
redhat.com MX preference = 20, mail exchanger = mx2.redhat.com
redhat.com MX preference = 10, mail exchanger = mx1.redhat.com

redhat.com nameserver = ns3.redhat.com
redhat.com nameserver = ns1.redhat.com
redhat.com nameserver = ns2.redhat.com
mx1.redhat.com internet address = 66.187.233.31
mx3.redhat.com internet address = 66.187.233.32
mx2.redhat.com internet address = 66.187.237.31
ns1.redhat.com internet address = 66.187.233.210
ns2.redhat.com internet address = 66.187.224.210
ns3.redhat.com internet address = 66.187.229.10

Redhat uses 3 MX records namely

mx1.redhat.com (Priority 10)
mx2.redhat.com (Priority 20)
mx3.redhat.com (Priority 10)

You can read their IP's in the DNS O/P above.

Any smtp deamon would first try and contact the mail server with a lower priority and then if it is not available a mail server with higher priority.

You can also do a DNS Round robin for other each MX record.

If there are MX records of equal priority then it is upto the smtp server to pick up on one of the records, there is no rule for this selection of atleast i know in the config files. :)

Next time on i will try and make a Dummy company ABC chemicals and then post a dummy snip from its .zone file for MX records.

Have a great weekend and remember dunn work the weekend.

Nitin :)

posted by Nitin @ 11/05/2004 01:04:00 PM