Networking problem

[Kevin J. Cummings]

On 05/14/2011 10:09 PM, JD wrote:
> On 05/14/11 18:45, James McKenzie wrote:
>> On 5/14/11 6:40 PM, JD wrote:
>>> On 05/14/11 18:24, Joe Zeff wrote:
>>>> On 05/14/2011 01:27 PM, JD wrote:
>>>>> I also brought the fedora firewall down, and retried to ping Fedora
>>>>> from Powerbook. No go!!
>>>> That means that it's not a firewall issue.  Check your router config to
>>>> see if it's set to allow pings inside the LAN.
>>> Thanx!
>>> I checked. The gateway has a built-in feature (program)
>>> to let you ping any client on the lan (or any ip on the public net).
>>> The gateway can ping both the powerbook and the fedora pc.
>>> no problems there.
>>> The fedora pc and the powerbook can ping the gw, and a third machine
>>> connected to the GW by ethernet, and can of course ping addresses
>>> on the public net.
>>> They (fedora pc and powerbook) cannot ping each other!
>>> Powerbook firewall is set to promiscuous mode.
>>> And as I had stated earlier, I even stopped iptables on the
>>> fedora pc, which puts it also in promiscuous mode (I assume).
>>> Still these two machines refuse to talk.
>>>
>> Can you use traceroute to communicate between the two of them?
>>
>> James McKenzie
>>
> Tried it.
> Tracerout is unable to get to target after 30 tries.
> All it shows is asterisks.

Sounds to me like traceroute is trying to go "direct" between machines....

Can you add a "special" static route between the 2 specifying the router
as the gateway?

As I recall, LAN traffic assumes that anything sent on the local
interface will get directly to anything else on the local network by
just sending it.  I'm not sure why the router doesn't "route" those
packets when it sees them unless it assumes that if receives them over
the wireless and the target machine is also wireless, that that would be
redundant.

Sometimes I used to set up static routes between machines, guaranteeing
that the route the packets take will get there.  something like:

On machine w.x.y.2, sending to machine w.x.y.3, using the router at
w.x.y.1 as the intermediary:

# route add -host w.x.y.3 gw w.x.y.1 dev eth0

I'm not 100% sure this will work, because if the router is at fault, it
may still fail.  But its worth a try.

-- 
Kevin J. Cummings
kjchome at verizon.net
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)