Redhat 9 network problem

nobodythere

First off, I'll admit to being a linux beginner (was once an intermediate but I got sick of computers for a few years).

Basically in my school we're setting up a web server for testing purposes and it's running RedHat 9. Long story short we're having lots of networking problems with the server. It's got Apache/PHP/MySQL set up on it and there are no problems connecting locally to this server (except for a ProFTPD issue but that's a different kettle of fish).

The machine can be pinged from other machines but it won't connect to any of the open ports on the machine. During setup I configured Linux to not enable any firewall and to double check this I ran the redhat-config-sercuritylevel tool too and disabled any sort of firewall protection. Still, I can't connect to any ports from any other machine but I can still ping the server from other machines.

Does anybody have any suggestions? I don't have total access to the rest of the network (being but a measly peasant) but according to them there's no internal firewall (can't say I can 100% go on their word)... Is it possible that the problem is still to do with the linux server?

My next try (only get at the computer once a week) is to set up Samba for file sharing (since file sharing is already functional across the windows computers) and if it'll connect to port 139 properly then I can determine whether it's a problem with the network or a problem with the server. Just thought I'd get some input on it first.

Please save your flames, as I said I'm no linux expert:) Thanks

osmethod

On the client you pinged from did you try the web browser with the ip of the RH9 box? e.g. http://192.168.0.1/

If so what was the reply?

Is the Apache service started and listening on all interfaces (initially)? On the server with an x terminal try netstat -na and see whats before :80, or if its there at all.

On your client you should be able to try telnettting to a port..

telnet 192.168.0.1 23
telnet 192.168.0.1 80
telnet 192.168.0.1 443

osmethod

micklum

See what services are started. try service --status-all |more This will show all services. You can start, stop or restart a service by service [name] stop or start or restart eg. if you want to restart the httpd service type service httpd restart

MMM

Khannie

Moved this one to the unix forum....more likely to get the answer you're looking for there.

My own input is that ping is a service too AFAIK, so at least one port is open. That would point to a firewall issue to me....

ronanp

scan the machine with nmap from itself and then from another machine. If you don't see the same ports open from both scans then its definately a firewall issue. In which case "/sbin/service iptables stop" from the server should sort ya.

nobodythere

To the first guy, I can ping the machine but have tried telnetting to ports 22 and 80 and neither of them work even though an nmap scan showed they are both running and can be accessed locally.

So the firewall isn't disabled with redhat-config-securitylevel? I'll try the command you said, and if that doesn't work I'll enable the firewall and set up rules to allow HTTP and SSH access.

Another idea occured to me to see if it's a firewall on the network or whether it's a firewall on the machine. I can just run tcpdump or ethereal and then see if it detects any packets when another computer tries to connect to the workstation.

Thanks for your help everybody!

nobodythere

Khannie wrote:

Moved this one to the unix forum....more likely to get the answer you're looking for there.

My own input is that ping is a service too AFAIK, so at least one port is open. That would point to a firewall issue to me....

Ping is sent in a different type of packet called ICMP, it's neither a TCP or UDP thing, and such the ICMP standard doesn't have ports, but thanks for the input. When a firewall disables pings it just discards all of these packets.

Khannie

That's my "thing" for today