Prevent kernel 2.6 ipv6 module from being loaded

I am running Red Hat 9 on Fujitsu Lifebook S6120 laptop. For
better ACPI support, I managed to upgrade to kernel
2.6.0-test9-mm1. I am quite satisfied with the improved
performance of the new kernel. But I found that some websites
became unable to respond to my browser's request properly
Either the connection request will be timed out, or the sites
just refuse my request. It looks like some out-of-date DNS
resolvers out there which can not properly handle ipv6 query are
the culprit. The ipv6 support is compiled as loadable module in
my kernel config (CONFIG_IPV6=m). Everytime when I boot, ipv6
module will always be loaded, and it won't be rmmod'ed even after
I shutdown network by 'service network stop', giving an error
"FATAL: Module ipv6 is in use."

It's strange that my old 2.4.20 kernel also has CONFIG_IPV6=m,
but the booting process won't load it since I don't set the
varialbe NETWORKING_IPV6 in the /etc/sysconfig/network config
file. Would anybody please tell me where/how I can prevent the
kernel 2.6 ipv6 module from being loaded automatically when booting?
Or the only solution for me is to disable it (CONFIG_IPV6=n) in the
very first when configuring the kernel?
Many thanks.

--Khoguan Phuann

KhoGuan PhuaN <(E-Mail Removed)> wrote:

[...]
> Would anybody please tell me where/how I can prevent the
> kernel 2.6 ipv6 module from being loaded automatically when booting?
> Or the only solution for me is to disable it (CONFIG_IPV6=n) in the
> very first when configuring the kernel?
> Many thanks.

Putting "alias net-pf-10 off" into /etc/modules.conf might help.

Ciao, Horst
--
»When pings go wrong (It hurts me too)« E.Clapton/E.James/P.Tscharn

Horst Knobloch <(E-Mail Removed)> wrote in message news:<bpqdes$21uh$(E-Mail Removed)>...
> KhoGuan PhuaN <(E-Mail Removed)> wrote:
> > Would anybody please tell me where/how I can prevent the
> > kernel 2.6 ipv6 module from being loaded automatically when booting?
> > Or the only solution for me is to disable it (CONFIG_IPV6=n) in the
> > very first when configuring the kernel?
>
> Putting "alias net-pf-10 off" into /etc/modules.conf might help.
>
> Ciao, Horst

Horst, thanks a lot for your kind help. Inspired by your
suggestion, I put "alias net-pf-10 off" into /etc/modprobe.conf
(kernel 2.6.0 uses modprobe.conf instead of modules.conf), rebooted,
and now the ipv6 module is not loaded again. Good.

It turns out that without ipv6 module being loaded, my real
problem still can not be solved--a few recalcitrant websites
don't respond to my http request under kernel 2.6 environment.
I just upgraded to the most current 2.6.0-test10 release even
without compiling ipv6 module. Then I tried this:

$ telnet www.edu.tw 80
Trying 140.111.1.192...

It hangs there without response until "Connection timed out."
And this

$ telnet www.readingtimes.edu.tw 80
Trying 210.200.236.42...
telnet: connect to address 210.200.236.42: Connection refused

It rejects my request right away. With Red Hat 9's 2.4.20 kernel
or 2.4.23-pre9 kernel I built by myself, these 2 sites respond
by showing their homepages.

For using kernel 2.6.0, I did upgrade several related packages
by checking Documentation/Changes and some net discussions about
Red Hat 9. I don't know whether the kernel, related packages
or rc files may cause the problem.

--Khoguan Phuann

KhoGuan PhuaN <(E-Mail Removed)> wrote:

> Horst Knobloch <(E-Mail Removed)> wrote in message
> news:<bpqdes$21uh$(E-Mail Removed)>...
>> KhoGuan PhuaN <(E-Mail Removed)> wrote:
[...]
> It turns out that without ipv6 module being loaded, my real
> problem still can not be solved--a few recalcitrant websites
> don't respond to my http request under kernel 2.6 environment.
> I just upgraded to the most current 2.6.0-test10 release even
> without compiling ipv6 module. Then I tried this:
[...]

If you only got problems with a few sites, you might try
echo "0" > /proc/sys/net/ipv4/tcp_ecn

If this works you could put "net.ipv4.tcp_ecn = 0"
into the file /etc/sysctl.conf, so at next reboot it should
be set automatically.


HTH

Ciao, Horst
--
»When pings go wrong (It hurts me too)« E.Clapton/E.James/P.Tscharn

Horst Knobloch <(E-Mail Removed)> wrote in message news:<bpvg10$2v9e$(E-Mail Removed)>...
> KhoGuan PhuaN <(E-Mail Removed)> wrote:
> > It turns out that without ipv6 module being loaded, my real
> > problem still can not be solved--a few recalcitrant websites
> > don't respond to my http request under kernel 2.6 environment.
>
> If you only got problems with a few sites, you might try
> echo "0" > /proc/sys/net/ipv4/tcp_ecn
>
> If this works you could put "net.ipv4.tcp_ecn = 0"
> into the file /etc/sysctl.conf, so at next reboot it should
> be set automatically.

OK, I turn off the Explicit Congestion Notification bit in the
IP header and the few problematic sites finally accept my http
request. Maybe a certain router/firewall somewhere between is
now happy to let my packets pass through. I really appreciate your
valuable help, Horst.

--Khoguan Phuann