two NICs again

Hello, there!

I have two NICs in my SuSE 8.1 box, one (connected to a CISCO 760 ISDN
router) configured to IP 192.168.0.1 mask 255.255.255.0, the other to
192.168.1.1, mask 255.255.255.0 connected to a local network with(at the
moment) 1 WIN2K box connected via an ovislink switch.
The CISCO is set to 192.168.0.254 and entered as standard gw in the routing
table, which looks loke this:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth1
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
default 192.168.0.254 0.0.0.0 UG 0 0 0 eth0


From the linux box I have internet access, and I can ping the second NIC,
but not the W2K box, which is set to address 192.168.1.2, however, I can
ping the second NIC from the WIN2K box.

I tried
ping -I 192.168.1.1 192.168.1.2
strange enough, there is no output to the console when the ping fails, I
just see the statistics as soon as I kill the ping with ctrl-c

Here is the ifconfig output:
linux:~ # ifconfig
eth0 Link encap:Ethernet HWaddr 00:00:21:61:8C:C4
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::200:21ff:fe61:8cc4/10 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:222 errors:0 dropped:0 overruns:0 frame:0
TX packets:1808 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:109963 (107.3 Kb) TX bytes:112924 (110.2 Kb)
Interrupt:9 Base address:0xe400

eth1 Link encap:Ethernet HWaddr 00:40:F4:96:15:10
inet addr:192.168.1.1 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::240:f4ff:fe96:1510/10 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4167 errors:0 dropped:0 overruns:0 frame:0
TX packets:2876 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:324730 (317.1 Kb) TX bytes:220152 (214.9 Kb)
Interrupt:9 Base address:0x3000

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:1623 errors:0 dropped:0 overruns:0 frame:0
TX packets:1623 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:142476 (139.1 Kb) TX bytes:142476 (139.1 Kb)

I'd be thankful for any ideas what's wrong here





Robert Stankowic

Robert Stankowic wrote:
> From the linux box I have internet access, and I can ping the second
NIC,
> but not the W2K box, which is set to address 192.168.1.2, however, I can
> ping the second NIC from the WIN2K box.

Which linux box? The same one you've been describing? Pinging the second
NIC is nothing special in that case, as it doesn't even go out on the
network. If you can ping from the w2k box, it sounds like your setup is
healthy (it certainly looks that way). Are you confused that the w2k box
doesn't reply to pings? It might be that it just isn't replying to
pings. I can't remember if that's default behavior in w2k or not, but it
certainly would be for example if you have the firewall enabled. To be
sure you could run ethereal on the w2k box and look for the incoming
ping packets... or better yet boot it with knoppix.

> I tried
> ping -I 192.168.1.1 192.168.1.2
> strange enough, there is no output to the console when the ping fails, I
> just see the statistics as soon as I kill the ping with ctrl-c

That's normal when the box you're pinging isn't replying.

Hans Fugal wrote:

> Robert Stankowic wrote:
[....]
>
> Which linux box? The same one you've been describing?

no, if you mean the elitegroup thingy. It's my own box, which I used
sometimes during the last year for some cross compiling. Meanwhile I
got a netgear access point and a few WLAN cards and decided to put
the linux box between my CISCO and the WLAN and fiddle around with a
bit more advanced networking under linux.

>Pinging the second
> NIC is nothing special in that case, as it doesn't even go out on
the
> network.

I know, I just wanted to see if the card is responding. Silly idea,
maybe.

>If you can ping from the w2k box, it sounds like your setup is
> healthy (it certainly looks that way). Are you confused that the w2k
box
> doesn't reply to pings? It might be that it just isn't replying to
> pings. I can't remember if that's default behavior in w2k or not,
but it
> certainly would be for example if you have the firewall enabled.

Aaaarrrgh, I feel so stupid. Thanks a lot for the hint, I had
completely forgotten that !@§$ firewall - it works now. I am pretty
sure, without your help it would have taken me hours to overcome that
blind spot.

Thank you again.

In message <40b31536$0$15516$(E-Mail Removed) lekom.at>,
Robert Stankowic wrote:

> Hello, there!
>
> I have two NICs in my SuSE 8.1 box, one (connected to a CISCO 760 ISDN
> router) configured to IP 192.168.0.1 mask 255.255.255.0, the other to
> 192.168.1.1, mask 255.255.255.0 connected to a local network with(at the
> moment) 1 WIN2K box connected via an ovislink switch.
> The CISCO is set to 192.168.0.254 and entered as standard gw in the
> routing table, which looks loke this:
>
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> 192.168.1.0 * 255.255.255.0 U 0 0 0
> eth1
> 192.168.0.0 * 255.255.255.0 U 0 0 0
> eth0
> default 192.168.0.254 0.0.0.0 UG 0 0 0
> eth0
>
>
> From the linux box I have internet access, and I can ping the second NIC,
> but not the W2K box, which is set to address 192.168.1.2, however, I can
> ping the second NIC from the WIN2K box.
>
This is RedHat-ese but I assume SuSe has a /proc subsystem as well.

On my router, "cat /proc/sys/net/ipv4/ip_forward" gives a 1. On the other
Linux boxes it doesn't. Have you enabled routeing through the box?

If you do "echo 1 > /proc/sys/net/ipv4/ip_forward" does it then all work?

Or am I thinking of something totally different? Also, does the Windows
machine have the Linux box as its default gateway?

Dave
--
mail: da (E-Mail Removed) (without the space)
http://www.llondel.org/
So many gadgets, so little time...

Dave {Reply Address in.sig} wrote:

> In message
<40b31536$0$15516$(E-Mail Removed) lekom.at>,
> Robert Stankowic wrote:
>
>> Hello, there!
>>
>> I have two NICs in my SuSE 8.1 box, one (connected to a CISCO 760
ISDN
>> router) configured to IP 192.168.0.1 mask 255.255.255.0, the other
to
>> 192.168.1.1, mask 255.255.255.0 connected to a local network
with(at the
>> moment) 1 WIN2K box connected via an ovislink switch.
>> The CISCO is set to 192.168.0.254 and entered as standard gw in the
>> routing table, which looks loke this:
>>
>> Kernel IP routing table
>> Destination Gateway Genmask Flags Metric Ref
Use
>> Iface
>> 192.168.1.0 * 255.255.255.0 U 0 0
0
>> eth1
>> 192.168.0.0 * 255.255.255.0 U 0 0
0
>> eth0
>> default 192.168.0.254 0.0.0.0 UG 0 0
0
>> eth0
>>
>>

[....]

> Or am I thinking of something totally different? Also, does the
Windows
> machine have the Linux box as its default gateway?

I seem to have several problems. The ping issue is solved now (I had
stupidly had the firewall on the W2K box block incoming ICMP
requests).

Now I can ping the Win-box from the unix box and vice versa, I can
also ping the other NIC in the linux box (which is in a different
subnet) from the WIn-box, but pinging the CISCO (192.168.0.254, same
subnet as the other NIC) from the WIn-box fails. I can, however, ping
the CISCO from the linux box.

Seems to be something wrong with my routing.
What also puzzles me is, that ifup eth0 as well as ifup eth1 show an
error message:

linux:/sbin # ifup eth0
ifup-route: Error while excuting:
ifup-route: Command 'ip route replace to 192.168.0.254/24 via
192.168.0.1 dev eth0' returned:
ifup-route: RTNETLINK answers: Invalid argument
ifup-route: Configuration line: 192.168.0.254 192.168.0.1
255.255.255.0 eth0
linux:/sbin # ifup eth1
ifup-route: Error while excuting:
ifup-route: Command 'ip route replace to 192.168.0.1/24 via
192.168.1.1 dev eth1' returned:
ifup-route: RTNETLINK answers: Invalid argument
ifup-route: Configuration line: 192.168.0.1 192.168.1.1
255.255.255.0 eth1

And here is the routing:

linux:/sbin # route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
192.168.1.0 * 255.255.255.0 U 0 0
0 eth1
192.168.0.0 * 255.255.255.0 U 0 0
0 eth0
default 192.168.0.254 0.0.0.0 UG 0 0
0 eth0

Any more ideas?
TIA