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-   -   eth0 works great, eth1 not working (http://www.linuxquestions.org/questions/linux-networking-3/eth0-works-great-eth1-not-working-807756/)

WonderLlama 05-14-2010 01:46 AM

eth0 works great, eth1 not working
 
Ok, so eth0 is up and working great. eth1, however, comes up with a link light, however the packet counters in ifconfig remain at 0. Appears that eth1 isn't working. Here's my setup:

-Dell latitude CPi laptop with 2 PCMCIA network cards and no built-in ethernet.
-Slackware v11
-eth0 is connected inside my router on my 192 network. Static address with good connectivity
-eth1 is connected on the other side of my router in promiscuous mode in order to listen to the traffic coming into my network.

Troubleshooting so far: I have switched the pcmcia cards between slots and regardless of which card is in eth0 or eth1, eth0 works and eth1 does not. I have also switched the card dongle between cards as well as the ethernet cabling between the cards. With any of the combinations eth0 works like a champ but eth1 does not, so I think I've ruled out hardware problems.

At this point I think it's a configuration problem with the eth1 interface but I don't know where to start to diagnose the problem. Sure would appreciate any ideas from the group. Thanks.

TB0ne 05-14-2010 10:53 AM

Quote:

Originally Posted by WonderLlama (Post 3967950)
Ok, so eth0 is up and working great. eth1, however, comes up with a link light, however the packet counters in ifconfig remain at 0. Appears that eth1 isn't working. Here's my setup:

-Dell latitude CPi laptop with 2 PCMCIA network cards and no built-in ethernet.
-Slackware v11
-eth0 is connected inside my router on my 192 network. Static address with good connectivity
-eth1 is connected on the other side of my router in promiscuous mode in order to listen to the traffic coming into my network.

Troubleshooting so far: I have switched the pcmcia cards between slots and regardless of which card is in eth0 or eth1, eth0 works and eth1 does not. I have also switched the card dongle between cards as well as the ethernet cabling between the cards. With any of the combinations eth0 works like a champ but eth1 does not, so I think I've ruled out hardware problems.

At this point I think it's a configuration problem with the eth1 interface but I don't know where to start to diagnose the problem. Sure would appreciate any ideas from the group. Thanks.

Have you tried just typing in "sudo ifconfig eth1 up"? Could be that the interface is down. And does that interface have a static or DHCP address?

WonderLlama 05-14-2010 01:49 PM

Interface is indeed up. Shows 'up' on ifconfig. interface is also set for static, not dhcp,and the ip address also shows up on ifconfig. Everything I can see from ifconfig and the physical HW indicates that it's up, but it just doesn't see the traffic (of which there is a lot...verified with wireshark on seperate computer).

I can also successfully ping the address on eth1 from the console.

Here is the output from ifconfig -a


Code:

eth0      Link encap:Ethernet  HWaddr 00:50:8B:59:A4:01
          inet addr:192.168.1.10  Bcast:192.168.1.255 Mask:255.255.255.0
          inet6 addr: fe80::250:8bff:fe59:a401/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:17781 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2909 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1530083 (1.4 MiB)  TX bytes:475513 (464.3 KiB)
          Interrupt:3 Base address:0x300

eth1      Link encap:Ethernet  HWaddr 00:10:A4:06:43:0B
          inet addr:10.1.1.2  Bcast:10.255.255.255  Mask:255.0.0.0
          inet6 addr: fe80::210:a4ff:fe06:430b/64 Scope:Link
          UP BROADCAST RUNNING NOARP PROMISC MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b)  TX bytes:468 (468.0 b)
          Interrupt:5 Base address:0x310


WonderLlama 05-15-2010 01:54 AM

Some more troubleshooting...

I can ping the eth1 interface from the console. When I connect another laptop to the same hub (not switch) as the eth1 laptop I am unable to ping the eth1 interface, nor can the eth1 interface ping the other laptop (both addresses are on the same subnet (10.1.0.x).

So I attached wireshark to the hub to see the traffic. When I initiate the ping from the laptop I see the arp request go on the line but there is no arp reply. So I removed the "noarp" setting from eth1. No change.

Then I tried to ping the laptop from eth1. wireshark sees the arp request from eth1 and the arp reply from the laptop, however the eth1 interface sends out another arp request as if it never received the arp response from the laptop.

So I checked the arp table on eth1 laptop. For the 10.1.0.x address the arp entry does not have a mac address. Rather under HWaddress it has (incomplete). I can flush the entries and try again but each time it comes back as (incomplete).

Sounds to me like eth1 is not receiving any data from the network, but can send data out. This is the case regardless of the network card as I have swapped the two PCMCIA cards and eth1 (now on the other card) has the same problem. So the problem sticks with eth1, not the card.

I hope that someone out there can offer some suggestions....

kaushalpatel1982 05-15-2010 07:11 AM

Looks like you have some strange problem. Not related to OS or Hardware. I suggest you to change the network cable and try it again. If possible try to connect machine back to back with cross cable and ping each other. If it's working, then put it back on the hub you have and check the same.

bathory 05-15-2010 07:42 AM

Are you sure that eth1 IP address 10.1.1.2 is correct?
Because in post #4 you mention 2 times the 10.1.0.x subnet.

WonderLlama 05-22-2010 11:54 PM

Good catch, bathory. In fact, I have been switching the IP address around as I troubleshoot, but to answer your question, the addresses are correct. The latest ones were 10.1.1 subnet.

Here's the latest. I think I've narrowed it down to some sort of configuration error, however I have no idea where to make the changes. The specific problem is that eth1 won't receive ANY packets, however it CAN transmit packets. I've verified this with both tcpdump and wireshark. My test setup follows:
Both eth0 and eth1 on the same network - eth0 192.168.1.10 / eth1 192.168.1.11
Both eth0 and eth1 plugged into the same switch with the router.
Ping from eth0 to 192.168.1.1 and receive a successful reply.
Ping from eth1 to 192.168.1.1 and receive destination not reachable
packet capture shows:
the arp request transmitted from eth1 to broadcast
the arp reply from 192.168.1.1
another arp request transmitted from eth1 to broadcast
another arp reply from 192.168.1.1
(the pattern continues without any response from eth1)
the tx counters on eth1 increase but the rx counters do not
(Kaushalpatel1982, I also tried to ping each interface from the other interface (eth0 to eth1 and vice versa). Pinging each interface without specifying the outbound interface (no -I option) each responds successfully. BUT when I specify the outbound interface with the -I option to send packets from eth0 over the wire to eth1 I get the same destination not reachable error.)

I downed eth0 and attempted the ping from eth1 just for grins and still saw no reply to eth1.

As mentioned before I've swapped out the pcmcia card, dongle, cables, and switch ports and the problem remains with eth1, not with the hardware. Therefore my conclusion is that the problem lies in the configuration of eth1. Additionally, both cards use the same driver: xirc2ps_cs.

Any hints on the files I can access to modify the eth1 configuration (slackware 11)? Sure would appreciate any hints as this is getting rather frustrating...

Gene

bathory 05-25-2010 08:54 AM

You can edit /etc/rc.d/rc.inet1.conf and configure eth1.

WonderLlama 05-27-2010 12:16 AM

I think I've pretty much exhausted the options in /rc.d/eth1.conf. Do you think it would make a difference if the module was compiled INTO the kernel vice loaded during boot? I hesitate to recompile the kernel just to test this theory so some advice would be welcome. Thanks.

bathory 05-27-2010 02:06 AM

Hi,

No, I don't think that compiling the driver into kernel will help.
What happens if you swap IPs instead of cards? I.e assign 192.168.1.10to eth1 and whatever IP to eth0
Also you can use mii-tool to play with eth1 settings

matpe 05-27-2010 10:17 AM

Quote:

Originally Posted by WonderLlama (Post 3978096)
The specific problem is that eth1 won't receive ANY packets, however it CAN transmit packets.

I have seen this problem several times before, but for different reasons. I can see three possible causes:

1) Bad driver or cards, that can't handle two cards at the same time. But then I have very little knowledge about the xirc2ps_cs driver.

2) I have seen this problem when running virtual machines that had somehow gotten the same MAC address on two machines. This causes some conflicts which causes the switch to send packets to the wrong machine.

3) Bad cables or a bad hub in your case. Sometimes these laptops with their PCMCIA cards cannot handle the voltage drops when connecting with low quality cables and hubs. Try connecting with high quality cables and to a real switch.

WonderLlama 05-27-2010 10:28 AM

bathory - I swapped IPs between the two interfaces and there was no change. eth0 still had a successful ping and eth1 did not. I've not heard of the mii tool so I'll check that out.

matpe - Thanks for the suggestions. Here are the results:
1. I'll look around for a different xirc2ps_cs driver. The one I'm using is the one that came with the distro. Maybe it's bad???
2. Not running on a VM, but I verified that each card has a separate MAC address, both through ifconfig and by looking at packets with wireshark.
3. Switched out the cable with a short, high quality cable to a switched port on my wireless router. Unfortunately there was no change.

I'll try the mii-tool and changing the driver. Hope I can get this working.

PatriceJ 07-17-2010 03:02 PM

I have the same problem ! and still have not find the solution

muzammel 02-03-2011 03:51 PM

I have also facing the same problem on VM with two interfaces eth1, not responding, and same happen arp request shows incomplete entry, i verified the mac addresses but found no duplication/confilct, can any one got the solution yet of this problem ? Please suggest.

Thanks
Muzi.

captainentropy 02-03-2011 05:18 PM

I actually had a very similar problem on a computer with dual LAN ports (built in). It turned out that LAN2 in the BIOS had somehow been disabled. There were other issues that problem precipitated that but aren't relevant in your case I don't think. Is there an option in the BIOS to disable a PCMCIA slot? If so perhaps the one is disabled.


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