Very Computer

I am having a cable connection and a linux server as router/server with two
eth cards, where i have MS-Windows machine connected on private
(192.168.1.x) network.
Currently the linux machine is running 2.4.20 kernel with firewall rules for
masq. Everythg works well where i can access internet from my MS Windows
machine etc. until recently when I upgraded my linux machine with 2.4.21
kernel and i found that MS-windows m/c unable to access the internet any
more. I didn't make any changes to firewall rules neither much changes to
/usr/src/linux/.config while building 2.4.21 kernel (new additions were
AMANDA and TFTP modules) wrt 2.4.20 /usr/src/linux/.config file.

Has anyone else observed this kind of issue with kernel 2.4.21?
Comments/suggestions.

Thanks
Praveen

How much experience do you have in configuring / compiling kernels? Was
the 2.4.20 a custom kernel you configured, or did it come from your
distro? Was the .config file from the previously-running 2.4.20 kernel,
or was it generated from the 2.4.21 defaults?

I suspect a misconfigured kernel. If you're right, and you did all of it
correctly, I would suggest that you back up the .config file, run "make
mrproper", restore the .config file, and run "make oldconfig dep bzImage
modules". Then install the kernel and modules, reboot, et c.

If that fails, this is an issue for the LKML.
--

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Well, i have been compiling kernels for last 12 years. The 2.4.20 kernel was
configured with default settings. The .config file was from the previously
running 2.4.20 kernel and I added 'amanda + tftp' modules for 2.4.21 kernel
configuration.
When I boot with 2.4.21 build kernel, it boots up with no errors, and I can
ping to the internet as well as samba mount disks from the MS-windows
machines (on intranet). The intranet machines can ping the linux server, but
internet is unreachable.

Looking forward to comments/suggestions.
Thanks
Praveen

Please forgive me: I don't mean to be rude, but this is surprising,
because in that amount of time I would have expected better
troubleshooting skills to have developed. You are NOT a newbie, but
these posts make you sound like one.

Quote:> Looking forward to comments/suggestions.

1. Are your netfilter drivers built as modules? Are they loaded?
2. "iptables-save"? Are the NAT rules correct?
3. Are the clients using DHCP? Is the correct routing being assigned?
   Rule out other DHCP-related issues? DNS? Can they ping outside IP's?
4. Did you look around in /proc? /proc/sys? /proc/net?
   "echo 1 > /proc/sys/net/ipv4/ip_forward"?
5. Did you try something like ethereal or tcpdump to see what happens?
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Try compiling 2,4,21 without any changes  and if that also fails
look at any differances betueen the two conifgs.  I'm suspecting
something that was default in 2,4.20  is not part of the 2.4.21
default. or maybe a module issue ???

This seems a bit unfair.
As I understood it, he used the same .config file for 2.4.21
as for 2.4.20 and networking didn't work properly.
It seems to me perfectly reasonable to ask if anyone has any suggestions.

I was just looking at my config files for 2.4.20 and 2.4.21
and I don't see any relevant changes.

If you can communicate with local machines,
then the problem must be in the routing,
or possibly in nat/iptables.

What does "route" say,
and what is the output of lsmod --
can you compare them with the outputs in 2.4.20 ?

--
Timothy Murphy  

tel: +353-86-233 6090
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland