I have a home network with one small server (as Internet router), connected to a cable modem on one side and wireless router Trendnet TEW-425BRP on the other, which is used as AP only.

The devices in the network are as follows:

1. Laptop with BCM4311 wireless card, running Fedora 10.
2. Desktop with RaLink RT2561/RT61 wireless card, running Fedora 10.
3. Nokia n810 with Conexant cx3110x, running latest Maemo.
4. Brother wired MFC with Ethernet adapter, plugged in the router.
5. mini-PC with 2 Ethernet cards running NetBSD and serving as an Internet router/server.

Firewalls on all machines, but the the NetBSD (router of the Internet) are off.

The reason I am listing them all is that is to point the problem. Initially when I try to ping from wireless to wireless (say from 1 to 2 or 2 to 3 or 1 to 3) I get "Host Unreachable", but if I ping from both a wired machine, then they can ping each other. Internet is accessible anywhere in the network -- no problem with that. Only when there was no direct connection between the wireless hosts for a longer time I can not ping from/to another wireless. Especially between the two 2 Fedora 10 machines.

I have checked all configurations and routing tables and they seem fine.
There must be something with the wireless or the set up of the devices (drivers) that I am missing.

What could be the problem?
Thanks in advance!

You also say you have checked all configurations... did this include your firewall settings?

Yes. The firewall is simple and does not restrict ranges of IPs. I other words there is no specific rule for the wireless machines.

etzvetanov - correct me if I have misinterpreted. The only issue you have is seeing machines that are connected via wireless and have not had a direct connection for an extended amount of time? Those machine however are able to "see" the server and internet?

If these are the case, you may want to see if there is a firmware upgrade for the wireless router.

Thanks for the suggestion, but I did a while ago. Same difference.

I read somewhere (I think it was another post in one other Linux forum) that if you eliminate the encryption (I use WPA), this problem is not showing, but there were no specifics for the interfaces and the network.

Anyway... It might have something to do with the settings of the wireless interfaces themselves... Something I'm missing.