Problem with Realtek 8139(It sends ARP but the reply is lost)

I have a desktop machine with a Realtek 8139 ethernet card. I also have
a laptop and a router.

Now when I connect my desktop to my router directly everything works
fine. But I want to share my internet connection and hence installed a
switch. This is where the problem started. My laptop is working fine on
the network and can ping my router. But the desktop just is not being
seen.

So I setup ethereal trace on both my laptop as well as the desktop. Now
when I ping the laptop from the desktop I can see the ARP messages on
the laptop to which it sends a normal reply. But the trace on the
desktop only shows outgoing ARPs and no replies.

To ensure that this was not only a Linux issue, I tried the same
experiment with windows XP on the desktop with the same result. So it
is definitely not a driver problem.

To ensure that there is no problem with the switch I connected the two
systems through a cross cable. Again I pinged from the desktop to the
laptop. The result was the same. The ARP replies were being sent
correctly but was not seen on the desktop.

What could be the problem?

(E-Mail Removed) wrote:
> I have a desktop machine with a Realtek 8139 ethernet card. I also have
> a laptop and a router.
>
> Now when I connect my desktop to my router directly everything works
> fine. But I want to share my internet connection and hence installed a
> switch. This is where the problem started. My laptop is working fine on
> the network and can ping my router. But the desktop just is not being
> seen.
>
> So I setup ethereal trace on both my laptop as well as the desktop. Now
> when I ping the laptop from the desktop I can see the ARP messages on
> the laptop to which it sends a normal reply. But the trace on the
> desktop only shows outgoing ARPs and no replies.
>
> To ensure that this was not only a Linux issue, I tried the same
> experiment with windows XP on the desktop with the same result. So it
> is definitely not a driver problem.
>
> To ensure that there is no problem with the switch I connected the two
> systems through a cross cable. Again I pinged from the desktop to the
> laptop. The result was the same. The ARP replies were being sent
> correctly but was not seen on the desktop.
>
> What could be the problem?
>
It looks as if your laptop doesn't know the route to your desktop (i.e.
local). That is normally set up by your DHCP server which is normally on
the router. Ethereal should show the MAC destination in the laptop
responses.

Robert

i dont see how that is the case. Since in ethereal i can see that the
message is going out correctly with the right MAC address.

Also the desktop is unable to see the router either.
Robert Harris wrote:
> (E-Mail Removed) wrote:
> > I have a desktop machine with a Realtek 8139 ethernet card. I also have
> > a laptop and a router.
> >
> > Now when I connect my desktop to my router directly everything works
> > fine. But I want to share my internet connection and hence installed a
> > switch. This is where the problem started. My laptop is working fine on
> > the network and can ping my router. But the desktop just is not being
> > seen.
> >
> > So I setup ethereal trace on both my laptop as well as the desktop. Now
> > when I ping the laptop from the desktop I can see the ARP messages on
> > the laptop to which it sends a normal reply. But the trace on the
> > desktop only shows outgoing ARPs and no replies.
> >
> > To ensure that this was not only a Linux issue, I tried the same
> > experiment with windows XP on the desktop with the same result. So it
> > is definitely not a driver problem.
> >
> > To ensure that there is no problem with the switch I connected the two
> > systems through a cross cable. Again I pinged from the desktop to the
> > laptop. The result was the same. The ARP replies were being sent
> > correctly but was not seen on the desktop.
> >
> > What could be the problem?
> >
> It looks as if your laptop doesn't know the route to your desktop (i.e.
> local). That is normally set up by your DHCP server which is normally on
> the router. Ethereal should show the MAC destination in the laptop
> responses.
>
> Robert

(E-Mail Removed) wrote:
> i dont see how that is the case. Since in ethereal i can see that the
> message is going out correctly with the right MAC address.
>
> Also the desktop is unable to see the router either.

What is your network topology (IP addresses, physical connections) and
what do you get when you type:

route -n

on your desktop?

Robert

> Robert Harris wrote:
>> (E-Mail Removed) wrote:
>>> I have a desktop machine with a Realtek 8139 ethernet card. I also have
>>> a laptop and a router.
>>>
>>> Now when I connect my desktop to my router directly everything works
>>> fine. But I want to share my internet connection and hence installed a
>>> switch. This is where the problem started. My laptop is working fine on
>>> the network and can ping my router. But the desktop just is not being
>>> seen.
>>>
>>> So I setup ethereal trace on both my laptop as well as the desktop. Now
>>> when I ping the laptop from the desktop I can see the ARP messages on
>>> the laptop to which it sends a normal reply. But the trace on the
>>> desktop only shows outgoing ARPs and no replies.
>>>
>>> To ensure that this was not only a Linux issue, I tried the same
>>> experiment with windows XP on the desktop with the same result. So it
>>> is definitely not a driver problem.
>>>
>>> To ensure that there is no problem with the switch I connected the two
>>> systems through a cross cable. Again I pinged from the desktop to the
>>> laptop. The result was the same. The ARP replies were being sent
>>> correctly but was not seen on the desktop.
>>>
>>> What could be the problem?
>>>
>> It looks as if your laptop doesn't know the route to your desktop (i.e.
>> local). That is normally set up by your DHCP server which is normally on
>> the router. Ethereal should show the MAC destination in the laptop
>> responses.
>>
>> Robert
>

Hi,

First I would like to thank you for taking time out to help. I have
been wrecking my brain over it for the past 4 days without any luck.

Here is my n/w topology

192.168.1.101 192.168.1.1
192.168.1.100
255.255.255.0
255.255.255.0
Laptop Router
Desktop
| |
|
| |
|
---------------------------------Switch----------------------------------------------

the route set at my desktop is -
Destination Gateway Genmask Flags Metric Ref Use
Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0
eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0
eth0


my laptop also has the very same route setting but its network works
just fine.

Thanks,
Akshat


Robert Harris wrote:
> (E-Mail Removed) wrote:
> > i dont see how that is the case. Since in ethereal i can see that the
> > message is going out correctly with the right MAC address.
> >
> > Also the desktop is unable to see the router either.
>
> What is your network topology (IP addresses, physical connections) and
> what do you get when you type:
>
> route -n
>
> on your desktop?
>
> Robert
>
> > Robert Harris wrote:
> >> (E-Mail Removed) wrote:
> >>> I have a desktop machine with a Realtek 8139 ethernet card. I also have
> >>> a laptop and a router.
> >>>
> >>> Now when I connect my desktop to my router directly everything works
> >>> fine. But I want to share my internet connection and hence installed a
> >>> switch. This is where the problem started. My laptop is working fine on
> >>> the network and can ping my router. But the desktop just is not being
> >>> seen.
> >>>
> >>> So I setup ethereal trace on both my laptop as well as the desktop. Now
> >>> when I ping the laptop from the desktop I can see the ARP messages on
> >>> the laptop to which it sends a normal reply. But the trace on the
> >>> desktop only shows outgoing ARPs and no replies.
> >>>
> >>> To ensure that this was not only a Linux issue, I tried the same
> >>> experiment with windows XP on the desktop with the same result. So it
> >>> is definitely not a driver problem.
> >>>
> >>> To ensure that there is no problem with the switch I connected the two
> >>> systems through a cross cable. Again I pinged from the desktop to the
> >>> laptop. The result was the same. The ARP replies were being sent
> >>> correctly but was not seen on the desktop.
> >>>
> >>> What could be the problem?
> >>>
> >> It looks as if your laptop doesn't know the route to your desktop (i.e.
> >> local). That is normally set up by your DHCP server which is normally on
> >> the router. Ethereal should show the MAC destination in the laptop
> >> responses.
> >>
> >> Robert
> >

(E-Mail Removed) wrote:
> Hi,
>
> First I would like to thank you for taking time out to help. I have
> been wrecking my brain over it for the past 4 days without any luck.
>
> Here is my n/w topology
>
> 192.168.1.101 192.168.1.1
> 192.168.1.100
> 255.255.255.0
> 255.255.255.0
> Laptop Router
> Desktop
> | |
> |
> | |
> |
> ---------------------------------Switch----------------------------------------------
>
> the route set at my desktop is -
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0
> eth0
> 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0
> eth0
> 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0
> eth0
>
>
> my laptop also has the very same route setting but its network works
> just fine.
>
> Thanks,
> Akshat
>
You need to take the line starting 169.254.0.0 out of your routing table
(which says that all IP addresses of the form 169.254.x.x are local,
which they are not).

Robert

>
> Robert Harris wrote:
>> (E-Mail Removed) wrote:
>>> i dont see how that is the case. Since in ethereal i can see that the
>>> message is going out correctly with the right MAC address.
>>>
>>> Also the desktop is unable to see the router either.
>> What is your network topology (IP addresses, physical connections) and
>> what do you get when you type:
>>
>> route -n
>>
>> on your desktop?
>>
>> Robert
>>
>>> Robert Harris wrote:
>>>> (E-Mail Removed) wrote:
>>>>> I have a desktop machine with a Realtek 8139 ethernet card. I also have
>>>>> a laptop and a router.
>>>>>
>>>>> Now when I connect my desktop to my router directly everything works
>>>>> fine. But I want to share my internet connection and hence installed a
>>>>> switch. This is where the problem started. My laptop is working fine on
>>>>> the network and can ping my router. But the desktop just is not being
>>>>> seen.
>>>>>
>>>>> So I setup ethereal trace on both my laptop as well as the desktop. Now
>>>>> when I ping the laptop from the desktop I can see the ARP messages on
>>>>> the laptop to which it sends a normal reply. But the trace on the
>>>>> desktop only shows outgoing ARPs and no replies.
>>>>>
>>>>> To ensure that this was not only a Linux issue, I tried the same
>>>>> experiment with windows XP on the desktop with the same result. So it
>>>>> is definitely not a driver problem.
>>>>>
>>>>> To ensure that there is no problem with the switch I connected the two
>>>>> systems through a cross cable. Again I pinged from the desktop to the
>>>>> laptop. The result was the same. The ARP replies were being sent
>>>>> correctly but was not seen on the desktop.
>>>>>
>>>>> What could be the problem?
>>>>>
>>>> It looks as if your laptop doesn't know the route to your desktop (i.e.
>>>> local). That is normally set up by your DHCP server which is normally on
>>>> the router. Ethereal should show the MAC destination in the laptop
>>>> responses.
>>>>
>>>> Robert
>

Robert Harris wrote:

> You need to take the line starting 169.254.0.0 out of your routing
> table (which says that all IP addresses of the form 169.254.x.x are
> local, which they are not).

Here is some background on 169.254/16

Request for Comments: 3927
Dynamic Configuration of IPv4 Link-Local Addresses
http://www.rfc-editor.org/rfc/rfc3927.txt

To participate in wide-area IP networking, a host needs to be
configured with IP addresses for its interfaces, either manually by
the user or automatically from a source on the network such as a
Dynamic Host Configuration Protocol (DHCP) server. Unfortunately,
such address configuration information may not always be available.
It is therefore beneficial for a host to be able to depend on a
useful subset of IP networking functions even when no address
configuration is available. This document describes how a host may
automatically configure an interface with an IPv4 address within the
169.254/16 prefix that is valid for communication with other devices
connected to the same physical (or logical) link.

Hi,

Thanks, for the replies. I have solved my issue. I just changed the PCI
slot of my ethernet card and all is fine.

Cheers,
aks
Spoon wrote:
> Robert Harris wrote:
>
> > You need to take the line starting 169.254.0.0 out of your routing
> > table (which says that all IP addresses of the form 169.254.x.x are
> > local, which they are not).
>
> Here is some background on 169.254/16
>
> Request for Comments: 3927
> Dynamic Configuration of IPv4 Link-Local Addresses
> http://www.rfc-editor.org/rfc/rfc3927.txt
>
> To participate in wide-area IP networking, a host needs to be
> configured with IP addresses for its interfaces, either manually by
> the user or automatically from a source on the network such as a
> Dynamic Host Configuration Protocol (DHCP) server. Unfortunately,
> such address configuration information may not always be available.
> It is therefore beneficial for a host to be able to depend on a
> useful subset of IP networking functions even when no address
> configuration is available. This document describes how a host may
> automatically configure an interface with an IPv4 address within the
> 169.254/16 prefix that is valid for communication with other devices
> connected to the same physical (or logical) link.

On Mon, 05 Jun 2006 01:55:56 -0700, akshatc rearranged some electrons to
form:

> I have a desktop machine with a Realtek 8139 ethernet card. I also have
> a laptop and a router.
>
> Now when I connect my desktop to my router directly everything works
> fine. But I want to share my internet connection and hence installed a
> switch. This is where the problem started. My laptop is working fine on
> the network and can ping my router. But the desktop just is not being
> seen.
>
> So I setup ethereal trace on both my laptop as well as the desktop. Now
> when I ping the laptop from the desktop I can see the ARP messages on
> the laptop to which it sends a normal reply. But the trace on the
> desktop only shows outgoing ARPs and no replies.
>
> To ensure that this was not only a Linux issue, I tried the same
> experiment with windows XP on the desktop with the same result. So it
> is definitely not a driver problem.
>
> To ensure that there is no problem with the switch I connected the two
> systems through a cross cable. Again I pinged from the desktop to the
> laptop. The result was the same. The ARP replies were being sent
> correctly but was not seen on the desktop.
>
> What could be the problem?

Set the Realtek card to half-duplex, 10Mbps. I had a problem once
with a similar cards' auto-negotiate not working correctly.
Hard-setting the configuration fixed the problem.


--
David M (dmacchiarolo)
http://home.triad.rr.com/redsled
T/S 53
sled351 Linux 2.4.18-14 has been up 3 days 21:31