3 DNS server problem, need advice

[anay]

I checked my DNS record at dns reports and found 3 following problems :

1...
[

Open DNS servers

Well, I will look into this one at HOW to section so basically its not a problem.

2.

Reverse DNS entries for MX records:

No PTR records exist for xxx.xxx.xxx.xxx. [Neg TTL=900 seconds]

where xxx.xxx.xxx.xxx is my server IP.
So how do I fix this one, which record I have to add and where. !

2.

WARNING: One or more of your mailservers is claiming to be a host other than what it really is (the SMTP greeting should be a 3-digit code, followed by a space or a dash, then the host name). This probably won't cause any harm, but is a technical violation of RFC821 4.3 (and RFC2821 4.3.1). Note that the hostname given in the SMTP greeting should have an A record pointing back to the same server.

Now I am little confused about DNS thing so I think I have messed up server host name etc. Wht is the possible problem ?

 

[nobaloney]

I checked my DNS record at dns reports and found 3 following problems :

1. Open DNS servers

Don't forget that if you change your DNS server so it won't do recursive lookups you can't use it in your /etc/resolv.conf file but will need some other server on the same network (usually provided by your upstream).

2. Reverse DNS entries for MX records:

Usually you have to get your upstream to provide your reverse DNS. Most upstream providers don't delegate it to you.

2. WARNING: One or more of your mailservers is claiming to be a host other than what it really is

Without seeing the greeting I can't tell you why, but doing reverse DNS to match your hostname A record for the same IP# will probably resolve this problem.

Jeff

 

[anay]

Basically I am very noob in DNS thing, it always emberasses me ,

Well, during DA install i have FQDN as servera.mydomain.com !
but as i have to use www.mydomain .com for a site . So I looked for www.mydomain .com dns entry it was not there.
instead there was servera.mydomain.com !

Now my little mind thaught that there is DNS records for servera.mydomain.com but in order to use www.mydomain .com I need to put sepeart dns record for it and it may conflict servera.mydomain.com ! so I removed servera.mydomain.com and added new www.mydomain .com .

Also the greeting says :
www.anothermydomain.com is pointing to non existing servera.mydomain.com

So I think basically there is no entry for servera.mydomain.com so there is such error.

What if I add a subdomain as servera.mydomain.com to existing record of www.mydomain .com ? or I need to add seperate record for servera.mydomain.com !

Also One doubt about DNS i have that ..

Say we have a dns record for www.mydomain .com then can I hv some other server (differetn physical mahcine hosting subdomain.mydomain.com !

It will only required to add DNS recorcd like to main server (ie. where the domain's is pointing namservers) .

subdomain IN A xxx.xxx.xxx.xxx

where xxx.xx.xxx.xxx is IP of other server ?

 

[nobaloney]

If you really want help you'll post real IP#s and your real domain name.

Jeff