Topic: DNS in SME 5.5 Broke!

[Marco Ranieri]

Hello all. I have installed an e-smith 5.5 box at an office, set up as a "Server and Gateway". It uses a DSL line with static IP. The clients also use static IPs.

The system worked great for a couple of weeks, now users have reported that their Internet does not work, they can't get mail, etc.

I logged into via SSH and found the following:

1. Can ping the server via its IP and hostname
2. Can ping all hosts on the LAN by IP, not by hostname
3. Can ping web sites via IP, not by host name

I seriously suspect that the server's DNS is screwed up. If it can't even resolve hostnames on the local LAN I know the problem is serious. Has anyone got any ideas? Is there a way to fix the DNS without re-install?

TIA!

Marco

[Bill Talcott]

Have you tried rebooting? Perhaps issue a "/sbin/e-smith/signal-event post-upgrade" first to make the server rebuild the files? Have you made any changes to it? Are the clients set up properly to use the SME for DNS?

[Marco Ranieri]

Bill, thanks for your reply. I already have tried issuing a "/sbin/e-smith/signal-event post-upgrade" then rebooting. The clients were up and running for two weeks, then - boom! the server's dns stopped working. Nothing I can see out of the ordinary except that it does not work anymore.

Hmmmmmmmmmm.....

[rob wellesley]

is named running?

# ps -aux | grep dns

should show the process ruuning

[dave]

Well, I'd say if you can ping the server by it's host name (not 'localhost' right?), DNS is working.  I'd check the DNS servers your SME is pointing at for external (internet) name resolution.

For internal name resolution... How are you assigning your static IP's?  If you're using DHCP with an IP assignment based on the requesting machine's MAC address, you might want to check that your DHCP is sending the proper DNS IP address.  If you've setup your clients with all manual entries for IP and DNS, I'm pretty sure you'll need to include the client names/IP's in your servers hosts file for local network name resolution.  I don't know if SME requires templates for that or not.  

DNS will cache lookups for a while, my guess is it worked initally, then a minor change was made and it took a couple weeks for the cached DNS entries to drop.

I found that DNS/DHCP issues are such a pain to deal with on Linux that I use a Windows server for integrated DHCP/DNS/WINS services (DON'T FLAME ME! I'm new to Linux, been working with MS for years - I'm learing but it's a pretty steep curve).  IP's are assigned dynamically and their names are automatically entered in DNS and WINS.  The win box has my ISP assigned DNS IP's as forewarding DNS addys which handles external name resolution.

I hope you'll let us all know what you find out...