[ILUG] Routing problem

[Kevin Philp]

John Allen wrote:
> Kevin wrote:
>> John Allen wrote:
>>> Kevin wrote:
>>>> I am having problems with my Debian/Lenny firewall/routing box. The 
>>>> internet connection runs really, really slow. It does work - but 
>>>> its very slow.
>>>>
>>>> My internal lan is 192.168.100.*
>>>> My DSL router is 192.168.1.254
>>>> My external nic (wireless) is 192.168.1.1
>>>> My internal nic is 192.168.100.1
>>>>
>>>> I checked the routing table:
>>>>
>>>> Kernel IP routing table
>>>> Destination     Gateway         Genmask         Flags Metric Ref    
>>>> Use Iface
>>>> 192.168.100.0   *               255.255.255.0   U     0      
>>>> 0        0 eth0
>>>> 192.168.1.0     *               255.255.255.0   U     0      
>>>> 0        0 wlan0
>>>> default         192.168.1.254   0.0.0.0         UG    0      
>>>> 0        0 wlan0
>>>>
>>> Your default route is the wireless connection, I'd guess the 
>>> wireless connection is the issue.
>>>>
>>>> Ifconfig/iwconfig look OK. However if I run traceroute I get some 
>>>> odd results:
>>>>
>>>> traceroute to an internal LAN address completes in 1 hop
>>>>
>>>> traceroute to the DSL router 192.168.1.254 from the firewall box 
>>>> fails after about 30 hops - it should be 1 hop.
>>>>
>>>> Running tracepath on the DSL box gives me:
>>>>
>>>> server:/home/kevinphilp# tracepath 192.168.1.254
>>>> 1:  192.168.1.1 (192.168.1.1)                              1.218ms 
>>>> pmtu 1500
>>>> 1:  no reply
>>>> 2:  no reply
>>>>
>>>> On google I get the same
>>>> server:/home/kevinphilp# tracepath www.google.com
>>>> 1:  192.168.1.1 (192.168.1.1)                              0.950ms 
>>>> pmtu 1500
>>>> 1:  no reply
>>>> 2:  no reply
>>>>
>>>> Any thoughts welcome
>>>>
>>>> Kevin.
>>>>
>>>
>> There does seem to be something wrong with it - the signal quality is 
>> claims to get from the access point is about 50% - which is weak 
>> considering the access point is about 15 feet away. Also it 
>> constantly backs off the rate from 54M down to 1M - my guess is 
>> either the wireless card or the router are decrepit - does that sound 
>> reasonable?
>>
> I've had a similar problem with my Laptop (Ubuntu Intrepid), was 
> getting 1M all the time until very recently, when some kernel update 
> fixed it. Still rarely get 54Mbps, but between 24 and 36.
>
> I'd direct wire the Deb box to the DSL modem/router (thats what I've 
> done), so at least the LAN is fast.

I had the box hard wired before and that was fine - but the family don't 
like ethernet cables run across hallways! I am surprised I got away with 
it as long as I did.

I am looking into the driver issue.

lspci tells me :
00:12.0 Network controller: RaLink RT2500 802.11g Cardbus/mini-PCI (rev 01)

Actually its a rt2560F chip on an Edimax EW-7128g card

lsmod tells me I have the following installed

rt2500pci              17152  0
rt2x00pci               7680  1 rt2500pci
rt2x00lib              22272  2 rt2500pci,rt2x00pci

My kernel is
Linux server 2.6.26-1-486 #1 Sat Jan 10 17:46:23 UTC 2009 i586 GNU/Linux

So it looks like we have the right driver running.

I actually checked on a similar machine with a lan connection and I get 
the same "no reply" from tracepath - so I guess that's actually not 
telling me anything. I seem to have got it running stably at 2M - I will 
tweak it up slowly and see what happens.

Kevin.