[ltp] WiFi on T42 (eth1 --> AP connection problems)
linux-thinkpad@linux-thinkpad.org
linux-thinkpad@linux-thinkpad.org
Sun, 16 Jan 2005 17:27:17 -0800 (PST)
Hello,
--- morpheus <morpheus@post.harvard.edu> wrote:
> On Sat, 2005-01-15 at 16:55 -0800, ogjunk-linuxtp@yahoo.com wrote:
> > I think my problem is even more basic. :)
> > That is, if I take down eth0, bring up eth1, ensure the correct
> route,
> > I still can't ping.... can't even ping the router:
>
> Sorry, I thought you said in a previous post that if you set the IP
> address of eth1 manually, you were able to ping the router. Are you
> saying that you can't do this:
> # ping -I eth1 192.168.0.1
Yes, I did say I could ping the router... I think I did ping it, but I
can't ping it now. I went back to that email I sent and I didn't
actually include the output of that ping, so it is possible that I made
a mistake when I said I was pinging the router and I was actually just
pinging myself/WiFi IF (192.168.0.3) when I thought I was pinging the
AP/router (192.168.0.1).
> > # Remove the extra default route (the one that didn't use metric)
> > [root@localhost otis]# route del default
> > [root@localhost otis]# route
> > Kernel IP routing table
> > Destination Gateway Genmask Flags Metric Ref
> Use
> > Iface
> > 192.168.0.0 * 255.255.255.0 U 0 0
> 0
> > eth1
> > 192.168.0.0 * 255.255.255.0 U 0 0
> 0
> > eth0
> > 169.254.0.0 * 255.255.0.0 U 0 0
> 0
> > eth0
> > default 192.168.0.1 0.0.0.0 UG 1 0
> 0
> > eth1
> > default 192.168.0.1 0.0.0.0 UG 2 0
> 0
> > eth0
>
> Yes, this looks perfect. You have no problem with the routing table.
> It seems we're back to diagnosing a simple connectivity issue between
> the interface and the access point.
Yes, I'm afraid we are. :(
> > [root@localhost otis]# ping 66.94.234.13 -I eth1
> > PING 66.94.234.13 (66.94.234.13) from 192.168.0.3 eth1: 56(84)
> bytes of
> > data.
> > >From 192.168.0.3 icmp_seq=1 Destination Host Unreachable
>
> Even more evidence to confirm the above. However, if you could run:
> # traceroute -i eth1 66.94.234.13
> We can know for sure.
Here it is:
# traceroute 66.94.234.13 -i eth1
traceroute to 66.94.234.13 (66.94.234.13), 30 hops max, 38 byte packets
1 192.168.0.3 (192.168.0.3) 3000.079 ms !H 3000.138 ms !H 3000.410
ms !H
> > Don't my routing tables look correct now?
>
> Yes, definitely.
>
> > > You could use different subnets...but this doesn't seem to be an
> > > option for you since your AP is on the same subnet as your wired
> LAN.
> >
> > My AP's IP is: 192.168.0.1. eth0 is 192.168.0.2 and eth1 is
> currently
> > 192.168.0.3. I could manually set the IP for eth1 to be, say,
> > 192.168.1.3, if that would make things easier.
>
> You'd also have to change the IP of the AP to the 192.168.1.0 subnet.
> If
> the AP has a built-in router, you can then have it route your packets
> to the 192.168.0.0 subnet.
I have Netgear MR814, which has a router, but I don't see any options
for manipulating routing in its web-based admin application. I do see
a way to set its LAN IP, it's IP subnet mask and that's about it for
IP-related stuff.
> However, as your problem now appears to be the
> connection between the AP and the IF, I would hold off on doing this
> since it will probably not solve the problem.
Yes.
> > Well, let me thank you one more for your patience! I really
> appreciate
> > it. Would you (or anyone else) happen to have an example of a
> routing
> > table with both eth0 and eth1/wlan0 on the same subnet and going
> out
> > through the single gateway, so that packets go over either eth0 or
> > eth1, depending on whether the computer is plugged into the network
> or
> > is near an AP?
>
> Your routing table as posted here looks fine. To summarize, with the
> routing table set as shown above, please provide the following info:
> 1. Results of: # ping -I eth1 192.168.0.1
> 2. Results of: # traceroute -i eth1 192.168.0.1
> 3. Results of: # ifconfig
> 4. Results of: # iwconfig
> 5. Is your AP also your router? A quick "sketch" of how everything
> is connected would help.
Here it is, starting with the sketch:
[My T42 with eth0 + eth1(WiFi)] [AP/Router/DHCP server] <--> WAN
^ ^ ^ ^ ^
| |------ eth1 ------| | |
|------------- eth0 ----------| |
|
|
[Wife's laptop with WiFi] <----------------------
IPs:
AP/Router/DHCP server: 192.168.0.1
T42 eth0: 192.168.0.2
T42 eth1: 192.168.0.3
Wife's laptop: 192.168.0.4
I configured the AP to always give the same IPs to same Mac addresses.
The AP does see all 3 interfaces (Wife's WiFi, my eth0 and my eth1) as
'attached devices', so some kind of a connection _is_ established
between eth1 and AP.
Wife's laptop WiFi works (Winblows XP). My T42 also has Winblows XP on
it, and the WiFi works fine there - so the actual WiFi hardware is OK.
Ping and traceroute (note errors/warnings for both when I use them as a
regular, non-root user):
$ ping 192.168.0.1 -I eth1
Warning: cannot bind to specified iface, falling back: Operation not
permitted
PING 192.168.0.1 (192.168.0.1) from 192.168.0.2 eth1: 56(84) bytes of
data.
>From 192.168.0.3 icmp_seq=1 Destination Host Unreachable
>From 192.168.0.3 icmp_seq=2 Destination Host Unreachable
>From 192.168.0.3 icmp_seq=3 Destination Host Unreachable
--- 192.168.0.1 ping statistics ---
4 packets transmitted, 0 received, +3 errors, 100% packet loss, time
2999ms
, pipe 4
Note the mention of 'from 192.168.0.2' above. Weird, no? .0.2 is
eth0, not eth1!
[otis@localhost ~]$ traceroute 192.168.0.1 -i eth1
setsockopt: Operation not permitted
unable to bind to device: eth1
I'm not sure why I'm getting these errors... but if I ping and
traceroute as root, I don't get them, nor the weird/wrong mention of
.0.2 IP, when I'm trying to go through eth1 (.0.3)):
[root@localhost otis]# ping -I eth1 192.168.0.1
PING 192.168.0.1 (192.168.0.1) from 192.168.0.3 eth1: 56(84) bytes of
data.
>From 192.168.0.3 icmp_seq=1 Destination Host Unreachable
>From 192.168.0.3 icmp_seq=2 Destination Host Unreachable
>From 192.168.0.3 icmp_seq=3 Destination Host Unreachable
--- 192.168.0.1 ping statistics ---
4 packets transmitted, 0 received, +3 errors, 100% packet loss, time
2998ms
, pipe 4
[root@localhost otis]# traceroute 192.168.0.1 -i eth1
traceroute to 192.168.0.1 (192.168.0.1), 30 hops max, 38 byte packets
1 192.168.0.3 (192.168.0.3) 3000.183 ms !H 3000.513 ms !H 3000.605
ms !H
Finally, ifconfig and iwconfig outputs:
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:11:25:12:18:EE
inet addr:192.168.0.2 Bcast:192.168.0.255
Mask:255.255.255.0
inet6 addr: fe80::211:25ff:fe12:18ee/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2474 errors:0 dropped:0 overruns:0 frame:0
TX packets:2420 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1134224 (1.0 MiB) TX bytes:311783 (304.4 KiB)
Base address:0x8000 Memory:c0220000-c0240000
eth1 Link encap:Ethernet HWaddr 00:0C:F1:59:B4:3D
inet addr:192.168.0.3 Bcast:192.168.0.255
Mask:255.255.255.0
inet6 addr: fe80::20c:f1ff:fe59:b43d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:149 dropped:128 overruns:0 frame:0
TX packets:228 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:9600 (9.3 KiB)
Interrupt:11 Base address:0x6000 Memory:c0214000-c0214fff
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:1756 errors:0 dropped:0 overruns:0 frame:0
TX packets:1756 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1880634 (1.7 MiB) TX bytes:1880634 (1.7 MiB)
# /sbin/iwconfig
lo no wireless extensions.
eth0 no wireless extensions.
eth1 IEEE 802.11b ESSID:"Wireless"
Nickname:"localhost.localdomain"
Mode:Managed Frequency:2.412GHz Access Point:
00:09:5B:29:41:3F
Bit Rate=11Mb/s Tx-Power:off
Retry:on RTS thr:off Fragment thr:off
Encryption key:1234-5678-4243-4331-3142-0000-00 Security
mode:open
Power Management:off
Link Quality=100/100 Signal level=-36 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:21 Missed beacon:0
sit0 no wireless extensions.
> We're getting closer to the answer...I don't think the issue is with
> the routing table.
Yes, I agree. This is my first WiFi on a Linux box... :)
Thank you,
Otis