I am learning my way around RH ES v3. After installing the OS, I moved the system from a downstream switch so that it was then connected directly to the router/gateway. I did this for physical location, not because of any other difficulty.

After moving the system, I immediately noticed that Mozilla was unable to connect (in fact during boot it was also unable to connect to the time server or the RH network in general).

To make things even more odd, I was still able to log in with SSH from another machine. So, I dug through the RH configuration files - everything looked fine, everything pinged properly etc.

Finally, I logged into the router admin panel -with the RH machine and it was able to do this without any modifications to the configuration. After logging into the router admin panel (where everything looked fine), what do you know, the machine was then able to connect outside the LAN again (e.g. this site). To be clear, after installation, before moving the system, it connected to the WWW flawlessly. After I moved the machine, it immediately could not connect to the WWW. Without changing anything, simply logging into the router admin panel, fixed the issue.

When I describe this event - the first thing I would suspect is the router being confused by the machine changing location, but I have never seen this behavior on a Windows machine. My next thought is, it looks like the IP address (once assigned during installation) is always static with RH. So maybe, the router didn't like the new path for the existing address, but this is speculation on my part.

Thats is, it seems like Windows OSes don't take an assigned IP address as static unless you specifically tell it to do so. Thus, when a Windows machine is moved, maybe it takes extra care to re-establish a connection with the router, where RH is just saying - hey this is my address now recognize that I have moved.

Anyway - sorry, I guess I am rambling/ speculating - can anyone provide some insight?

EDIT: OK - sorry, probably this is the wrong forum it shouldn't be RH specific.

Hi,

I presume that you have assigned a static IP address to your network interface. If so, the interface should come up reliably (OK at boot). The next issue is how to get from the interface to the rest of the world. You need to tell the OS the IP address of the gateway. I suspect that this is the problem.

Open the network section of the system settings. Double click on your device (e.g eth0). Then it will probably have the statically set IP addresses section selected. Therein you enter the IP address, subnet mask and default GATEWAY.

Try this first and see how it goes.

The routing table can be printed using the 'route' command. It should have an entry 'default' with an IP address for a gateway. You need to be able to reach (e.g ping) this address.

See, this is the thing - connected to my router I have a switch, then a WAP, a wireless bridge and then another switch. Both switches use the same default gateway (the router) 192.168.0.1

So, when I installed RH, the system was behind the wireless bridge, but had the exact same settings.

When I brought it forward, I connected it directly to the router - and it refused (for hours) to connect to the www.

So, the settings on the RH machine where all correct and it ended up I didn't have to change anything. Finally simply logging into the routers control panel got it working again.

I have just never seen this behavior on a windows machine (except when using static IPs then they get stubbern as well). But there doesn't seem to be a way to let RH have a truely dynamic IP (i.e. an IP that is request from the DHCP at every boot).