Disable ipv6.......

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Charlie

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Jan 2, 2014, 1:50:02 AM1/2/14
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Another thing I would like to do is to disable ipv6 on this system
as satellite doesn't use ipv6

Without doing ifdown eth0 to see if I was using ipv6, I did:


# rmmod ipv6

libkmod: ERROR ../libkmod/libkmod-module.c:1802
kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
such file or directory Error: Module ipv6 is in use

So there is ipv6 in use.

How can I disable it and if someone knows, how can that enabled again
should I want to do so?

Thank you,
Charlie
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when they were supplied with food and women, to escape the
tediousness of life. .....W. Somerset Maugham

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Ivan Jurišić

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Jan 2, 2014, 2:10:01 AM1/2/14
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Try this:

1. open file /etc/default/grub

nano /etc/default/grub

2 add "ipv6.disable=1" in variable GRUB_CMDLINE_LINUX_DEFAULT, example:

GRUB_CMDLINE_LINUX_DEFAULT="quiet ipv6.disable=1"

3. last step, update grup and reboot PC:

update-grub
reboot

Dana 02/01/2014 07:47, Charlie je napisao(la):

   Another thing I would like to do is to disable ipv6 on this system
   as satellite doesn't use ipv6

Without doing ifdown eth0 to see if I was using ipv6, I did:


# rmmod ipv6

libkmod: ERROR ../libkmod/libkmod-module.c:1802
kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
such file or directory Error: Module ipv6 is in use

So there is ipv6 in use.

How can I disable it and if someone knows, how can that enabled again
should I want to do so?

Thank you,
Charlie
    -- 
	Registered Linux User:- 329524
	***********************************************

	Art is merely the refuge which the ingenious have invented,
	when they were supplied with food and women, to escape the
	tediousness of life. .....W. Somerset Maugham

	***********************************************

	Debian GNU/Linux - just the best way to create magic

	-----------------------------------------------------


#

Charlie

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Jan 2, 2014, 2:10:01 AM1/2/14
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Apologies, let me say this before I resend it:

Running Jessie: 3.11-2-amd64 #1 SMP Debian 3.11.10-1 (2013-12-04)
x86_64 GNU/Linux

Toshiba c500/A00L w8 laptop

Another thing I would like to do is to disable ipv6 on this system
as satellite doesn't use ipv6

Without doing ifdown eth0 to see if I was using ipv6, I did:


# rmmod ipv6

libkmod: ERROR ../libkmod/libkmod-module.c:1802
kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
such file or directory Error: Module ipv6 is in use

So there is ipv6 in use.

How can I disable it and if someone knows, how can that enabled again
should I want to do so?

Thank you,
Charlie
--
Registered Linux User:- 329524
***********************************************

Art is merely the refuge which the ingenious have invented,
when they were supplied with food and women, to escape the
tediousness of life. .....W. Somerset Maugham

***********************************************

Debian GNU/Linux - just the best way to create magic

-----------------------------------------------------


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Charlie

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Jan 2, 2014, 2:30:01 AM1/2/14
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On Thu, 02 Jan 2014 07:58:24 +0100 Ivan Jurišić sent:

> Try this:
>
> 1. open file /etc/default/grub
>
> nano /etc/default/grub
>
> 2 add "ipv6.disable=1" in variable GRUB_CMDLINE_LINUX_DEFAULT,
> example:
>
> GRUB_CMDLINE_LINUX_DEFAULT="quiet ipv6.disable=1"
>
> 3. last step, update grup and reboot PC:
>
> update-grub
> reboot

Thank you Ivan,

Did that:

But I still get the same message:

# rmmod ipv6
libkmod: ERROR ../libkmod/libkmod-module.c:1802
kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
such file or directory Error: Module ipv6 is in use

Which I can only assume means that ipv6 is actually still in use,
unless it's tricking me of course? [laughing]

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government, intelligence is so highly honored that it is
rewarded by exemption from the cares of office. ......Ambrose
Bierce, The Devil's Dictionary

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Charlie

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Jan 2, 2014, 4:40:01 AM1/2/14
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On Thu, 2 Jan 2014 18:22:09 +1100 Charlie sent:

> On Thu, 02 Jan 2014 07:58:24 +0100 Ivan Jurišić sent:
>
> > Try this:
> >
> > 1. open file /etc/default/grub
> >
> > nano /etc/default/grub
> >
> > 2 add "ipv6.disable=1" in variable GRUB_CMDLINE_LINUX_DEFAULT,
> > example:
> >
> > GRUB_CMDLINE_LINUX_DEFAULT="quiet ipv6.disable=1"
> >
> > 3. last step, update grup and reboot PC:
> >
> > update-grub
> > reboot
>
> Thank you Ivan,
>
> Did that:
>
> But I still get the same message:
>
> # rmmod ipv6
> libkmod: ERROR ../libkmod/libkmod-module.c:1802
> kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
> such file or directory Error: Module ipv6 is in use
>
> Which I can only assume means that ipv6 is actually still in use,
> unless it's tricking me of course? [laughing]

Further to this tried:

echo 'blacklist ipv6' >> /etc/modprobe.d/blacklist

but received the same message as all the other times.

Did:

Ifdown eth0

then did:

# rmmod ipv6

Same error message:

libkmod: ERROR ../libkmod/libkmod-module.c:1802
kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
such file or directory Error: Module ipv6 is in use

Did:

net.ipv6.conf.all.disable_ipv6 = 1

in /etc/sysctl.conf

when I run:

sysctl -p

as root, I get this error message:


sysctl: cannot stat /proc/sys/net/ipv6/conf/all/disable_ipv6: No
such file or directory

So it has to be tricking me, because every line in /etc/sysctl.conf
ipv4 or ipv6 is commented out?

So it's trickin' or there is another file.

[sigh]
Charlie
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***********************************************

The cost of a thing is the amount of what I will call life
which is required to be exchanged for it, immediately or in the
long run. ........Henry David Thoreau

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Debian GNU/Linux - just the best way to create magic

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Ivan Jurišić

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Jan 2, 2014, 4:50:02 AM1/2/14
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If wont to check loaded modules in memory try:

lsmod or lsmod | grep ipv6

then if not find in output "ipv6" that module is not active.

also check with /sbin/ifconfig | grep inet if got any line with "inet6" in that case You have up & running ipv6.

Charlie

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Jan 2, 2014, 7:20:01 AM1/2/14
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On Thu, 02 Jan 2014 10:39:47 +0100 Ivan Jurišić sent:

> If wont to check loaded modules in memory try:
>
> lsmod

nf_conntrack 70753 7
nf_nat,xt_state,nf_nat_ipv4,xt_conntrack,nf_conntrack_
ftp,iptable_nat,nf_conntrack_ipv4

> or lsmod | grep ipv6

returns nothing?

> then if not find in output "ipv6" that module is not active.
>
> also check with /sbin/ifconfig | grep inet if got any line with
> "inet6" in that case You have up & running ipv6.

Nothing with 6 in it at all.

So my system is tricking me all right with that spurious message.

Thanks for your help,
Charlie
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***********************************************

The generative energy, which, when we are loose, dissipates and
makes us unclean, when we are continent invigorates and
inspires us. Chastity is the flowering of man; and what are
called Genius, Heroism, Holiness, and the like, are but various
fruits which succeed it.....Henry David Thoreau

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Charlie

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Jan 2, 2014, 7:40:02 AM1/2/14
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On Thu, 2 Jan 2014 18:08:49 +1100 Charlie sent:

> # rmmod ipv6
>
> libkmod: ERROR ../libkmod/libkmod-module.c:1802
> kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
> such file or directory Error: Module ipv6 is in use

Thank you Ivan and Pi for your help.

I think the message above is spurious, a remnant of something that has
not yet been updated from Wheezy.

I can't recall for certain, but this is how I usually do an install and
this is an install on a new machine.

I installed wheezy to get all the packages I wanted to use up and
running on the system. When I had it working the way I wanted, I
changed the /etc/apt/sources-list to jessie and updated and upgraded.
Then have the system I want up and running and work from there.

So I am certain now that I don't have ipv6 enabled at all, and that
message can be ignored.

Many thanks once again for your kindness.

I wish for you all the things you wish for yourselves in the new year.
Charlie
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misfortunes. ....Voltaire

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Bonno Bloksma

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Jan 2, 2014, 9:00:02 AM1/2/14
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Hello Charlie,

>> # rmmod ipv6
>>
>> libkmod: ERROR ../libkmod/libkmod-module.c:1802
>> kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
>> such file or directory Error: Module ipv6 is in use
>
> Thank you Ivan and Pi for your help.
>
> I think the message above is spurious, a remnant of something that has not yet been updated from Wheezy.
>
> [...]
>
> So I am certain now that I don't have ipv6 enabled at all, and that message can be ignored.

In previous Debian versions ipv6 was done via a module that one could unload or disable to prevent ipv6 being activated.
As of Squeeze ipv6 is built in at the kernel level and cannot be disabled that way.

So unless you are still running Lenny or build your own kernel there is no ipv6 module.
Just do "ip addr" or "ifconfig" and you will probably see ip6 lines, ip6 is default on now. If your uplink does not do ipv6 then there is no ipv6 traffic going over the line and no delay in using ipv4.

Bonno Bloksma


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Federico Alberto Sayd

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Jan 2, 2014, 10:20:02 AM1/2/14
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echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6


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Tom H

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Jan 2, 2014, 1:00:02 PM1/2/14
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On Thu, Jan 2, 2014 at 1:53 PM, Bonno Bloksma <b.bl...@tio.nl> wrote:
>>>
>>> # rmmod ipv6
>>>
>>> libkmod: ERROR ../libkmod/libkmod-module.c:1802
>>> kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
>>> such file or directory Error: Module ipv6 is in use
>>
>> So I am certain now that I don't have ipv6 enabled at all, and that message can be ignored.
>
> In previous Debian versions ipv6 was done via a module that one could unload or disable to prevent ipv6 being activated.
> As of Squeeze ipv6 is built in at the kernel level and cannot be disabled that way.
>
> So unless you are still running Lenny or build your own kernel there is no ipv6 module.
> Just do "ip addr" or "ifconfig" and you will probably see ip6 lines, ip6 is default on now. If your uplink does not do ipv6 then there is no ipv6 traffic going over the line and no delay in using ipv4.

When ipv6 is compiled as a module, you can disable it with modprobe or sysctl.

When ipv6 is compiled in-kernel, you can disable it in two ways.

You can disable the ipv6 stack by adding "ipv6.disable=1" to the kernel cmdline.

You can disable the assignment of ipv6 addresses to nics by adding
"ipv6.disable_ipv6=1" to the kernel cmdline.

The latter's the equivalent of creating "/etc/sysctl.d/disable_ipv6.conf" where

# cat /etc/sysctl.d/disable_ipv6.conf
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv6.conf.eth<X>.disable_ipv6=1

(or you can "echo 1 > /proc/sys/net/ipv6/conf/.../disable_ipv6" at boot)


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Charlie

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Jan 2, 2014, 3:40:02 PM1/2/14
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On Thu, 2 Jan 2014 17:55:50 +0000 Tom H sent:
Thank you all. I believe I was on a witch hunt.

I have disabled it on Windows machines for people who use satellite in
our area. To help them achieve better Internet performance. Just thought
I should be certain that, what I assumed, I'm not using it in Debian,
was correct.

I thought it wasn't an addition to my system, but after that spurious
message, doubts - doubts and more doubts.

Thought the beast better be hunted down and removed. Not being able to
find it, even after much googling as to commands that might flush it, or
how it might be recognised without any success at finding it in my
system.

Thought I better hand it to all you good people with greater knowledge
than myself, who have set my mind at rest. Proving it can't be
discovered. The reason being, it's not there except in the reply of that
message.

Thank you all.
Charlie
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Scott Ferguson

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Jan 5, 2014, 4:50:02 AM1/5/14
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On 03/01/14 04:55, Tom H wrote:
> On Thu, Jan 2, 2014 at 1:53 PM, Bonno Bloksma <b.bl...@tio.nl> wrote:
>>>>
>>>> # rmmod ipv6
>>>>
>>>> libkmod: ERROR ../libkmod/libkmod-module.c:1802
>>>> kmod_module_get_holders: could not open '/sys/module/ipv6/holders': No
>>>> such file or directory Error: Module ipv6 is in use
>>>
>>> So I am certain now that I don't have ipv6 enabled at all, and that message can be ignored.
>>
>> In previous Debian versions ipv6 was done via a module that one could unload or disable to prevent ipv6 being activated.
>> As of Squeeze ipv6 is built in at the kernel level and cannot be disabled that way.
>>
>> So unless you are still running Lenny or build your own kernel there is no ipv6 module.
>> Just do "ip addr" or "ifconfig" and you will probably see ip6 lines, ip6 is default on now. If your uplink does not do ipv6 then there is no ipv6 traffic going over the line and no delay in using ipv4.
>
> When ipv6 is compiled as a module, you can disable it with modprobe or sysctl.
>
> When ipv6 is compiled in-kernel, you can disable it in two ways.
>
> You can disable the ipv6 stack by adding "ipv6.disable=1" to the kernel cmdline.
>
> You can disable the assignment of ipv6 addresses to nics by adding
> "ipv6.disable_ipv6=1" to the kernel cmdline.
>
> The latter's the equivalent of creating "/etc/sysctl.d/disable_ipv6.conf" where
>
> # cat /etc/sysctl.d/disable_ipv6.conf
> net.ipv6.conf.all.disable_ipv6=1
> net.ipv6.conf.default.disable_ipv6=1
> net.ipv6.conf.eth<X>.disable_ipv6=1
>
> (or you can "echo 1 > /proc/sys/net/ipv6/conf/.../disable_ipv6" at boot)
>
>

I don't know that having IPv6 enabled but unused makes the system slower
but those instructions alone still leave IPv6 services running.

To see what uses IPv6 *and* is running:-
# netstat -tunlp |grep p6 |more
tcp6 0 0 :::22 :::*
LISTEN 3492/sshd
tcp6 0 0 :::445 :::*
LISTEN 3340/smbd
tcp6 0 0 :::139 :::*
LISTEN 3340/smbd
udp6 0 0 :::51849 :::*
2454/dhclient



For samba edit /etc/samba/smb.conf and uncomment the lines:-
; interfaces = 127.0.0.0/8 eth0
; bind interfaces only = yes

then:-
# service samba restart


For dhclient edit /etc/dhcp/dhclient.conf and replace:-
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
dhcp6.name-servers, dhcp6.domain-search,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;

with:-
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;

then:-
# service networking restart


For sshd:-
# echo "AddressFamily=inet" >> /etc/ssh/sshd_config

then:-
# service ssh restart

If you no longer have any IPv6 programs running you should get 0 from
the following:-
# netstat -tunlp |grep p6 |wc -l


The above examples work with Wheezy.

Kind regards




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Charlie

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Jan 5, 2014, 6:50:02 AM1/5/14
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On Sun, 05 Jan 2014 20:40:43 +1100 Scott Ferguson sent:

> To see what uses IPv6 *and* is running:-
> # netstat -tunlp |grep p6 |more

After that command - nothing - blank back screen with (END) in the
middle.

It's all good.

Thank you.
Charlie
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Charlie

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Jan 5, 2014, 7:00:02 AM1/5/14
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On Sun, 05 Jan 2014 20:40:43 +1100 Scott Ferguson sent:

> # netstat -tunlp |grep p6 |wc -l

Just says:


0

Thank you,
Charlie
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Tom H

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Jan 5, 2014, 4:50:01 PM1/5/14
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On Sun, Jan 5, 2014 at 9:40 AM, Scott Ferguson
<scott.ferguso...@gmail.com> wrote:
> On 03/01/14 04:55, Tom H wrote:
>>
>> When ipv6 is compiled as a module, you can disable it with modprobe or sysctl.
>>
>> When ipv6 is compiled in-kernel, you can disable it in two ways.
>>
>> You can disable the ipv6 stack by adding "ipv6.disable=1" to the kernel cmdline.
>>
>> You can disable the assignment of ipv6 addresses to nics by adding
>> "ipv6.disable_ipv6=1" to the kernel cmdline.
>>
>> The latter's the equivalent of creating "/etc/sysctl.d/disable_ipv6.conf" where
>>
>> # cat /etc/sysctl.d/disable_ipv6.conf
>> net.ipv6.conf.all.disable_ipv6=1
>> net.ipv6.conf.default.disable_ipv6=1
>> net.ipv6.conf.eth<X>.disable_ipv6=1
>>
>> (or you can "echo 1 > /proc/sys/net/ipv6/conf/.../disable_ipv6" at boot)
>
> I don't know that having IPv6 enabled but unused makes the system slower
> but those instructions alone still leave IPv6 services running.

As I said, the latter instructions disable the assignment of ipv6
addresses to the nics, not ipv6 itself.

If you want to disable applications' use of ipv6, you have to do so
application by application.


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