Strange routing table (solved).

[Erik P. Olsen]

Gordon Messmer wrote:
> Erik P. Olsen wrote:
> 
>> My main box is an FC3 linux box wire coupled to a Linksys router 
>> WRT54G. I have two laptops wireless coupled to the router. One laptop 
>> runs Windows 2000 the other Windows XP. The laptops can ping all boxes 
>> but the linux box can't ping the laptops.
> 
> 
> 
> Is your router assigning IPs from the same network to both the Linux 
> host and the wireless-attached hosts?  If so, you can use tcpdump 
> (install it if you need to) and make sure that the Windows hosts are 
> responding to ARP requests.
> 
> As an example, if I want to observe the arp and ping to 172.20.111.6 
> from my workstation (wanderlust), I might use this command:
> 
> # tcpdump arp or host 172.20.111.6
> 
> I could be more specific, but that will work.  Now, if I ping that host 
> in another terminal, I see these three lines printed from tcpdump:
> 
> 14:29:47.317821 arp who-has 172.20.111.6 tell wanderlust
> 14:29:47.317975 arp reply 172.20.111.6 is-at 00:11:11:74:ca:7b
> 14:29:47.317986 IP wanderlust > 172.20.111.6: icmp 64: echo request seq 0
> 
> The first two are examples of what you should see.  If you ping another 
> host in the same IP network, your workstation should request the MAC 
> address of the remote host.  If it doesn't reply, it's possible that 
> your router isn't bridging broadcast traffic between the wired and 
> wireless attached networks.  If *that* is the case, the best solution is 
> to configure the router to assign different IP networks to hosts in each 
> of the wired and wireless attached nets.
> 
Thanks for all your help. I have now found the reason to my problems. Being a 
newbie I wasn't aware that the iptables running on my linux box actually IS a 
firewall and that it blocked any connect attempt from outside (blush). When I 
opened for the port in question to tcp everything performed normally. It took me 
many days of agony before I realised what it was, sigh.

Again, thanks a lot.

-- 
Regards,
Erik P. Olsen