Topic: DNS Problem, part Deux

[m alden]

For over 5 weeks i had the settings for DNS in my e-smith box (dedicated, server only) set to nothing, using the caching only aspect of e-smith and having everything work fine.  Workstations were set to use the e-smith box as primary, and my freesco router as secondary.

Then, today, all of a sudden, my mail stopped going out.  Upon checking the Internet connectivity of my e-smith box, it could not ping out use F.Q. domain names, only ip's.  So, i rebooted the e-smith box, rebooted the router, and still, no Internet using domain names.

So, I set the DNS to use my service providers DNS (Boooo!), and now i get Internet connectivity, and my mail is going out.

What happened?  Why do I have to use my ISP's DNS?  How can I get back to only using my e-smith box?

thanks!
m alden

[Charlie Brady]

m alden wrote:

> So, I set the DNS to use my service providers DNS (Boooo!), and
> now i get Internet connectivity, and my mail is going out.
>
> What happened?  Why do I have to use my ISP's DNS?

Perhaps you should ask your service provider that? It sounds like they might be filtering DNS packets.

Other than that, look through /var/log/messages - if there is a software problem on your e-smith box, there might be some clues to what is going on there.

Charlie

[ewomack]

I happen to know that m alden's ISP does not use DNS filtering as we use the same service.  My e-smith box has not lost its ability to cache DNS, and I do not use the ISP's as a backup.  Could he possibly "manually" restart the daemon and/or flush the cache to clear out possible "bad" information?

[Mike Luckham]

Have a look at /var/named/named.ca, which contains lines like

A. ROOT-SERVERS.NET.   3600000  A  198.41.0.4

This is used to find the main DNS servers on the Internet, I believe.

I don't know if e-smith server tries to rebuild named.ca (it is recommended that this be done periodically) but in situtations where I have implemented a script to do so, and the script has failed, it has resulted in a near-empty named.ca file and the symptoms you mention.

[m alden]

Thanks for all of the suggestions!

Ok, I used vi to check through the /var/log/messages and the names.ca:   lots of stuff in the messages.  mostly "unapproved update from [internal IP add]".  Nothing else that makes sense to me.  What am I looking for in there.  There are 5 messages files in there.

In the names.ca, a long list of all of the host DNS address.  That was about it.  No idea how to reset that.

Can I set my primary and secondary to the first two in that list?  (198.41.0.4 & 128.9.0.107)  Thus bypassing my ISP's DNS?

thanks again!
M

[Charlie Brady]

m alden wrote:

> Ok, I used vi to check through the /var/log/messages and the

You should use "less" instead - you don't want to inadvertently edit a log file.

> names.ca:   lots of stuff in the messages.  mostly
> "unapproved update from [internal IP add]".

That just means that you have NT clients, I think. But it does mean that your named is running.

> Nothing else that makes sense to me.  What am I looking for in there.
> There are 5 messages files in there.

The others are old ones - not really relevant.

> In the names.ca, a long list of all of the host DNS address.
> That was about it.  No idea how to reset that.

You shouldn't need to.

> Can I set my primary and secondary to the first two in that
> list?  (198.41.0.4 & 128.9.0.107)  Thus bypassing my ISP's
> DNS?

Not usefully.

Do you have PrimaryDNS and Secondary DNS configured? If so, then set them both to "" and see how that goes. If not set, then set them to your ISP's primary and secondary and try that.

Here are some tests you can try:

dig SOA 0.0.127.in-addr.arpa
dig SOA e-smith.domain.name # But use your domain name
dig SOA domain.name

Regards

Charlie

[Gordon Rowell]

Mike Luckham wrote:

> Have a look at /var/named/named.ca, which contains lines like
>
> A. ROOT-SERVERS.NET.   3600000  A  198.41.0.4
>
> This is used to find the main DNS servers on the Internet, I
> believe.

True. It is used as hints to find the "root" nameservers. The
addresses listed in the hints are queried to find the current root
nameservers - it's only used for bootstrapping named.

> I don't know if e-smith server tries to rebuild named.ca

It doesn't.

> (it is recommended that this be done periodically)

The addresses of the root servers are effectively static, and the
named.ca is used only for bootstrap, so updating it every few
years is sufficient. The latest  one on ftp.rs.internic.net is Aug 22, 1997,
which is the one shipped with e-smith.

> but in situtations where I have implemented a script to do so, and
> the script has failed, it has resulted in a near-empty named.ca file and > the symptoms you mention.

named.ca gives details on where to get the latest version via FTP, which
should result in an atomic change to the file.

Gordon

[m alden]

dig SOA 0.0.127.in-addr.arpa   dig SOA e-smith.domain.name  dig SOA domain.name

I will try setting DNS back to blank,  and see if I can get out.