Networking problem

JD jd1008 at gmail.com
Sun May 15 04:18:36 UTC 2011


On 05/14/11 20:59, Kevin J. Cummings wrote:
> On 05/14/2011 11:42 PM, JD wrote:
>>> 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.
>>>
>> No that would not do anything because already the default route is
>> 192.168.1.254
>> which is the gateway/router.
> No.  The default route is only used when there is not a route found for
> the target machine.  If the target machine is on the same subnet, then
> the packets just get sent out on the local network device.  While its
> true that both the target machine and the router are on this network,
> this is the configuration that is not working for you.  What you want is
> to either add a specific route "before" the local network route so that
> all traffic to that machine gets sent to the router, or, remove your
> local network route from your routing table.  In that case, all you
> should have is a default route (that might work).
>
> This is my laptop routing table:
>> # route
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
>> local.net       *               255.255.255.0   U     2      0        0 eth1
>> default         192.168.6.1     0.0.0.0         UG    0      0        0 eth1
> Note that any traffic to my local network gets put on the local network.
>   (This is the first routing line.)  BTW, local.net is 192.168.6.0/24.
>
> If there is traffic for *anywhere* else, that's what invokes the default
> route, and that gets sent to my router.
>
> I'm suggesting that you either have:
>
> 192.168.1.108	192.168.1.254	255.255.255.0	UG	wlan0
> 192.168.1.0	*		255.255.255.0	U	wlan0
> 0.0.0.0		192.168.1.254	0.0.0.0		UG	wlan0
>
> or you have only:
>
> 0.0.0.0		192.168.1.254	0.0.0.0		UG	wlan0
>
> I think you'll see a difference....
>
> I'm also wondering if you'll have to do the something similar on the
> "other" wireless machine.... (192.168.1.108?)  I'm assuming your 2
> "wireless" machines are 192.168.1.60&  192.168.1.108, and that your
> router is 192.168.1.254.
>
I do not seem to be able to alter the routing table.
Current table on Fedora pc is:
$ route -vn
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use 
Iface
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 
wlan0
0.0.0.0         192.168.1.254   0.0.0.0         UG    0      0        0 
wlan0

I removed interfaces eth0 and virbr0 (i.e. I deactivated them) so they 
no longer
get configured at bootup.



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