Linode.com Forum

brlewis · Joined: 31 May 2004 Posts: 13

I'm hoping to use bind9 to run DNS myself. It looks like I get the right IP address back from dig @65.19.178.131 brlewis.com, but never having done this before I want to be sure I'm not doing some kind of subtle screwup. Anyone see a mistake in this master file for brlewis.com?

@ IN SOA ns1.brlewis.com. (
2004060101 ; Serial (yyyymmddxx)
86400 ; Refresh (1 day)
7200 ; Retry (2 hours)
604800 ; Expire (7 days)
86400 ) ; Minimum (1 day)

IN NS ns1.brlewis.com.

brlewis.com. IN A 65.19.178.131
www IN CNAME brlewis.com.

ns1 IN A 65.19.178.131

sweh · Joined: 13 Apr 2004 Posts: 234

brlewis wrote:
@ IN SOA ns1.brlewis.com. (
2004060101 ; Serial (yyyymmddxx)
86400 ; Refresh (1 day)
7200 ; Retry (2 hours)
604800 ; Expire (7 days)
86400 ) ; Minimum (1 day)

Aren't you missing an entry in this SOA record? After "ns1.brlewis.com." you need your contact address (with @ converted to .)

The format is
Code:
@ IN SOA origin mail.addr (
serial refresh retry expire ttl)

The line beginning "brlewis.com." may be better of using @ as the name, so it references implicitly the zone you are defining (same as with the SOA record) for consistency. But that's just a matter of taste :-)

brlewis · Joined: 31 May 2004 Posts: 13

I'll defer to someone else's taste. My DNS needs are so normal that I don't think I need to agonize over anything, or even get a deep understanding of all the RFCs.

@ IN SOA ns1.brlewis.com. brlewis.alum.mit.edu (
2004060101 ; Serial (yyyymmddxx)
86400 ; Refresh (1 day)
7200 ; Retry (2 hours)
604800 ; Expire (7 days)
86400 ) ; Minimum (1 day)

IN NS ns1.brlewis.com.

@ IN A 65.19.178.131
www IN CNAME brlewis.com.
ns1 IN A 65.19.178.131

brlewis · Joined: 31 May 2004 Posts: 13

I suppose though I should at least have an MX record. I also added a $TTL line because bind was noting its absence in syslog (falling back on min ttl).

Code: $TTL 1d
@ IN SOA ns1.brlewis.com. brlewis.alum.mit.edu (
2004061501 ; Serial (yyyymmddxx)
86400 ; Refresh (1 day)
7200 ; Retry (2 hours)
604800 ; Expire (7 days)
86400 ) ; Minimum (1 day)

IN NS ns1.brlewis.com.

@ IN A 65.19.178.131
@ IN MX 50 65.19.178.131
www IN CNAME brlewis.com.
ns1 IN A 65.19.178.131
ns2 IN A 65.19.178.131

sweh · Joined: 13 Apr 2004 Posts: 234

A quick glance and there's a few things. FIrstly, MX records should point to A records, not to IP addresses...

Code:
% nslookup -silent -type=mx brlewis.com 65.19.178.131
Server: 65.19.178.131
Address: 65.19.178.131#53

brlewis.com mail exchanger = 50 65.19.178.131.brlewis.com.

There are a couple of minor points you may not be aware of. The first is that since you have multiple entries for "@" they can all be collapsed into one.

The second is the CNAME for www. Because it's a CNAME you now also have MX records, NS records and SOA records for the "www" name etc etc

Code:
% nslookup -silent -type=mx www.brlewis.com 65.19.178.131
Server: 65.19.178.131
Address: 65.19.178.131#53

www.brlewis.com canonical name = brlewis.com.
brlewis.com mail exchanger = 50 65.19.178.131.brlewis.com.

It's just a minor point :-)

What I would do is:
Code: $TTL 1d
@ IN SOA ns1.brlewis.com. brlewis.alum.mit.edu (
2004061601 ; Serial (yyyymmddxx)
86400 ; Refresh (1 day)
7200 ; Retry (2 hours)
604800 ; Expire (7 days)
86400 ) ; Minimum (1 day)

IN NS ns1.brlewis.com.
IN A 65.19.178.131
IN MX 50 mail.brlewis.com.

; We use the same IP address a lot, because we use different
; names for the same service. We could just have
; "linode.brlewis.com" as the one name, but...
www IN A 65.19.178.131
ns1 IN A 65.19.178.131
ns2 IN A 65.19.178.131
mail IN A 65.19.178.131

Note that the same IP address is used in lots of places now. As the comment says, we _could_ reduce it and just have it twice (an A record for the @ line, and an A record for a general line (eg "linode") and have everything (NS, MX,WWW) all point to that. That's just a matter of taste :-)

wirehead · Joined: 03 Jun 2004 Posts: 23

And don't forget to do everybody a favor and create an SPF record. ;)

correct master file?