Ubuntu Server 10.04 Firewall Problem

[NewtownGuy]

Hello,

I'm calling this a firewall problem because I don't know what else to call it.

My machine will not accept any incoming connection requests and will not respond to ping. It acts as if a firewall were rejecting all incoming connection requests. However, all services are working because I have OpenVPN running on it as a client, and these services, such as Apache, Webmin, and SSH, work fine if I access them via the VPN.

I checked the firewall status in Webmin, and Webmin says the firewall is off. I executed 'ufw disable' from the command line as a double-check, but I still can't connect to the machine except via the VPN.

How can I enable incoming traffic on this machine ?

Thank you in advance.

-- NewtownGuy

 

[Noway2]

Are you using a router that is blocking the connection?

Run a traceroute ("traceroute <your-ip or domain>") and this will tell you the IP address of the last responding device which is where you will want to look first.

 

[NewtownGuy]

TO: Noway2

There's only an ethernet switch between the server and several PC's, none of which can access the server unless they use the VPN. The problem must be in the server, which used to work. Some piece of software must have broken.

-- NewtownGuy

 

[BIS]

try

service lokkit stop

 

[Noway2]

If your certain that there is no firewall and that your ISP is not blocking you, then the next thing to check would be whether or not the processes are running and if they are bound to the proper IP address / Ethernet adapter.

Use the commands netstat -nta and ps -aux (note, ubuntu may complain about a - here) and pipe them through grep, looking for the service port of interest, e.g.22 for ssh. See if it is bound to 0.0.0.0, or a particular adapter.

You night also want to do a list of the Iptable NAT table, ipables -L -t nat.

Note that all of the above commands will require root privilege to run.

 

[mrregan]

what are the contents of /etc/hosts.allow and
/etc/hosts.deny?