Resolving

[CCSI]

My server was behind a SonicWall firewall with the correct ports opened. The firewall went out on me, and while reading some posts here, I decided not to replace it, but rather start using iptables and kiss my firewall. (this was as of Wednesday of last week)

Now... over the last few days I have had customers saying that some people that sent them email last week, are not being able to get through this week. The error messages report that their servers were unable to resolve the domain.

I then logged into my fathers computer remotely... 800 miles away and was able to resolve. I then tried a free service in Czechoslovakia, and it resolved...

One of my techs was out onsite with a customer of ours that uses AT&T as their ISP. They can't resolve any over our domains, yet last week they were sending us email all the time.

Don't know if it is a fluke about the firewall, but needed someone smarter than me to toss a few ideas and things to try.


Also, my last post said that I was trying to get rhn to send me my account password. I am guessing that they too can't resolve my host.

any help is appreciated...

David

[ProWebUK]

Whoever is having the problems ask them to run a traceroute on your domain / mailserver (both should be as effective as each other!)

With the results of that you should be able to detect where the problem is occuring :)

Chris

[CCSI]

Thanks Chris,

It wont resolve the name so it can trace the route. It does work when I use the IP #

[ProWebUK]

Originally posted by CCSI
It wont resolve the name

can you ping the domain...?

- Check all of your DNS records are in place also.

Use http://www.dnsreport.com/tools/dnsreport.ch?domain=domain.com

To check everything is ok and main DNS records are there :)

Chris

[CCSI]

Chris,

Tried that... not troubles reported there.

That is a good tool. Glad to know it exists.


Still bewildered by why most resolve, but not all.


I sent you an email asking you to respond... I am sure you did, but I didn't get it either.

Dave

[CCSI]

Update:

I rebooted the server and emails started coming in from everywhere. Weird, but resolved (literally)

David