[gentoo-user] Disable IPv6 on specific interface

[gentoo-user] Disable IPv6 on specific interface

[Zesen Qian]

Hello list,
Sorry for hijacking Rich's thread, resend here.
I want to disable IPv6 on an certain interface, a simple google
tell me to add one line to /etc/sysctl.d/local.conf
net.ipv6.conf.enp4s0.disable_ipv6=1
Simple enough, but the problem I have is that both ipv6 and the
dirver of the network card(tg3) is loaded by modules. They 're not
loaded when the service sysctl is started, so there's no entry
named "net.ipv6.conf.enp4s0", which make sysctl not working.
So my question is that, is there any way to disable IPv6 on
specific interface, as early as I can? I want to make it early
because I don't want to receive any RA to mess up my route table.
I guess just adding sysctl to preup() in /etc/conf.d/net should do
the trick, but may I make it earlier?
Any comment is appreciated.

-- 
Zesen Qian (钱泽森)

Re: [gentoo-user] Disable IPv6 on specific interface

[Mick]

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On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
> Hello list,
> Sorry for hijacking Rich's thread, resend here.
> I want to disable IPv6 on an certain interface, a simple google
> tell me to add one line to /etc/sysctl.d/local.conf
> net.ipv6.conf.enp4s0.disable_ipv6=1
> Simple enough, but the problem I have is that both ipv6 and the
> dirver of the network card(tg3) is loaded by modules. They 're not
> loaded when the service sysctl is started, so there's no entry
> named "net.ipv6.conf.enp4s0", which make sysctl not working.
> So my question is that, is there any way to disable IPv6 on
> specific interface, as early as I can? I want to make it early
> because I don't want to receive any RA to mess up my route table.
> I guess just adding sysctl to preup() in /etc/conf.d/net should do
> the trick, but may I make it earlier?
> Any comment is appreciated.


Unless the kernel knows of the enp4s0 interface and therefore lists it under 
sysctl, I can't see how it can be disabled.  You could try disabling IPv6 
altogether in the kernel, but this may not be what you want to achieve.

Alternatively, have a look with modinfo in the module options in the unlikely 
chance that the module has some option which disables IPv6 functionality.

-- 
Regards,
Mick

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Re: [gentoo-user] Disable IPv6 on specific interface

[Zesen Qian]

Mick <michaelkintzios@gmail.com> writes:

> On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
>> Hello list,
>> Sorry for hijacking Rich's thread, resend here.
>> I want to disable IPv6 on an certain interface, a simple google
>> tell me to add one line to /etc/sysctl.d/local.conf
>> net.ipv6.conf.enp4s0.disable_ipv6=1
>> Simple enough, but the problem I have is that both ipv6 and the
>> dirver of the network card(tg3) is loaded by modules. They 're not
>> loaded when the service sysctl is started, so there's no entry
>> named "net.ipv6.conf.enp4s0", which make sysctl not working.
>> So my question is that, is there any way to disable IPv6 on
>> specific interface, as early as I can? I want to make it early
>> because I don't want to receive any RA to mess up my route table.
>> I guess just adding sysctl to preup() in /etc/conf.d/net should do
>> the trick, but may I make it earlier?
>> Any comment is appreciated.
>
>
> Unless the kernel knows of the enp4s0 interface and therefore lists it under 
> sysctl, I can't see how it can be disabled.  You could try disabling IPv6 
> altogether in the kernel, but this may not be what you want to achieve.
>
> Alternatively, have a look with modinfo in the module options in the unlikely 
> chance that the module has some option which disables IPv6 functionality.

Hello Mick,
The module ipv6 has only three parameters, each of which is "disable
ipv6", "disable ipv6 on all interfaces", "disable autoconf on all
interfaces", none of these is what I want to achieve. Module tg3 has
only on parameters which control the debug level.
Currently I just call "sysctl net.ipv6.conf.enp4s0.disable_ipv6=1" in
preup(), which works just fine. I 'm just wondering if there 's some
more "proper" way to do it. Since in my opinion, this should be done at
the first moment when the interface is present, not when the interface
is up.

-- 
Zesen Qian (钱泽森)

Re: [gentoo-user] Disable IPv6 on specific interface

[Mick]

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On Tuesday 30 Dec 2014 10:10:04 Zesen Qian wrote:
> Mick <michaelkintzios@gmail.com> writes:
> > On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
> >> Hello list,
> >> Sorry for hijacking Rich's thread, resend here.
> >> I want to disable IPv6 on an certain interface, a simple google
> >> tell me to add one line to /etc/sysctl.d/local.conf
> >> net.ipv6.conf.enp4s0.disable_ipv6=1
> >> Simple enough, but the problem I have is that both ipv6 and the
> >> dirver of the network card(tg3) is loaded by modules. They 're not
> >> loaded when the service sysctl is started, so there's no entry
> >> named "net.ipv6.conf.enp4s0", which make sysctl not working.
> >> So my question is that, is there any way to disable IPv6 on
> >> specific interface, as early as I can? I want to make it early
> >> because I don't want to receive any RA to mess up my route table.
> >> I guess just adding sysctl to preup() in /etc/conf.d/net should do
> >> the trick, but may I make it earlier?
> >> Any comment is appreciated.
> > 
> > Unless the kernel knows of the enp4s0 interface and therefore lists it
> > under sysctl, I can't see how it can be disabled.  You could try
> > disabling IPv6 altogether in the kernel, but this may not be what you
> > want to achieve.
> > 
> > Alternatively, have a look with modinfo in the module options in the
> > unlikely chance that the module has some option which disables IPv6
> > functionality.
> 
> Hello Mick,
> The module ipv6 has only three parameters, each of which is "disable
> ipv6", "disable ipv6 on all interfaces", "disable autoconf on all
> interfaces", none of these is what I want to achieve. 

Right, I didn't think that you would want to disable IPv6 completely, but 
mentioned it for completeness.


> Module tg3 has
> only on parameters which control the debug level.

Yes, I thought it unlikely that a hardware driver would be used to configure 
IPv6, but it was worth checking.


> Currently I just call "sysctl net.ipv6.conf.enp4s0.disable_ipv6=1" in
> preup(), which works just fine. I 'm just wondering if there 's some
> more "proper" way to do it. Since in my opinion, this should be done at
> the first moment when the interface is present, not when the interface
> is up.

I'm afraid I don't know of any other way to do it.

-- 
Regards,
Mick

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Re: [gentoo-user] Disable IPv6 on specific interface

[covici]

Mick <michaelkintzios@gmail.com> wrote:

> On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
> > Hello list,
> > Sorry for hijacking Rich's thread, resend here.
> > I want to disable IPv6 on an certain interface, a simple google
> > tell me to add one line to /etc/sysctl.d/local.conf
> > net.ipv6.conf.enp4s0.disable_ipv6=1
> > Simple enough, but the problem I have is that both ipv6 and the
> > dirver of the network card(tg3) is loaded by modules. They 're not
> > loaded when the service sysctl is started, so there's no entry
> > named "net.ipv6.conf.enp4s0", which make sysctl not working.
> > So my question is that, is there any way to disable IPv6 on
> > specific interface, as early as I can? I want to make it early
> > because I don't want to receive any RA to mess up my route table.
> > I guess just adding sysctl to preup() in /etc/conf.d/net should do
> > the trick, but may I make it earlier?
> > Any comment is appreciated.
> 
> 
> Unless the kernel knows of the enp4s0 interface and therefore lists it under 
> sysctl, I can't see how it can be disabled.  You could try disabling IPv6 
> altogether in the kernel, but this may not be what you want to achieve.
> 
> Alternatively, have a look with modinfo in the module options in the unlikely 
> chance that the module has some option which disables IPv6 functionality.

You may be able to use the feature of modprobe that executes a command
when the module loads and that way disable the ipv6 interface.  I have
not tried this myself.


-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com

Re: [gentoo-user] Disable IPv6 on specific interface

[Zesen Qian]

covici@ccs.covici.com writes:

> Mick <michaelkintzios@gmail.com> wrote:
>
>> On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
>> > Hello list,
>> > Sorry for hijacking Rich's thread, resend here.
>> > I want to disable IPv6 on an certain interface, a simple google
>> > tell me to add one line to /etc/sysctl.d/local.conf
>> > net.ipv6.conf.enp4s0.disable_ipv6=1
>> > Simple enough, but the problem I have is that both ipv6 and the
>> > dirver of the network card(tg3) is loaded by modules. They 're not
>> > loaded when the service sysctl is started, so there's no entry
>> > named "net.ipv6.conf.enp4s0", which make sysctl not working.
>> > So my question is that, is there any way to disable IPv6 on
>> > specific interface, as early as I can? I want to make it early
>> > because I don't want to receive any RA to mess up my route table.
>> > I guess just adding sysctl to preup() in /etc/conf.d/net should do
>> > the trick, but may I make it earlier?
>> > Any comment is appreciated.
>> 
>> 
>> Unless the kernel knows of the enp4s0 interface and therefore lists it under 
>> sysctl, I can't see how it can be disabled.  You could try disabling IPv6 
>> altogether in the kernel, but this may not be what you want to achieve.
>> 
>> Alternatively, have a look with modinfo in the module options in the unlikely 
>> chance that the module has some option which disables IPv6 functionality.
>
> You may be able to use the feature of modprobe that executes a command
> when the module loads and that way disable the ipv6 interface.  I have
> not tried this myself.

Hello Covici,
Yes, there's a rule named "install <modulename> [command..]" in
modprobe, but aren't they only applied to modprobe itself? I mean, in my
case the ipv6 and tg3 is loaded automatically(maybe by udev?), not by
running "modprobe ipv6". is this kind of module loading also affected by
modprobe rule(in /etc/modprobe.d/*.conf)?

-- 
Zesen Qian (钱泽森)

Re: [gentoo-user] Disable IPv6 on specific interface

[covici]

Zesen Qian <gentoo-user@dnspod-free.mydnspod.net> wrote:

> covici@ccs.covici.com writes:
> 
> > Mick <michaelkintzios@gmail.com> wrote:
> >
> >> On Tuesday 30 Dec 2014 03:27:34 Zesen Qian wrote:
> >> > Hello list,
> >> > Sorry for hijacking Rich's thread, resend here.
> >> > I want to disable IPv6 on an certain interface, a simple google
> >> > tell me to add one line to /etc/sysctl.d/local.conf
> >> > net.ipv6.conf.enp4s0.disable_ipv6=1
> >> > Simple enough, but the problem I have is that both ipv6 and the
> >> > dirver of the network card(tg3) is loaded by modules. They 're not
> >> > loaded when the service sysctl is started, so there's no entry
> >> > named "net.ipv6.conf.enp4s0", which make sysctl not working.
> >> > So my question is that, is there any way to disable IPv6 on
> >> > specific interface, as early as I can? I want to make it early
> >> > because I don't want to receive any RA to mess up my route table.
> >> > I guess just adding sysctl to preup() in /etc/conf.d/net should do
> >> > the trick, but may I make it earlier?
> >> > Any comment is appreciated.
> >> 
> >> 
> >> Unless the kernel knows of the enp4s0 interface and therefore lists it under 
> >> sysctl, I can't see how it can be disabled.  You could try disabling IPv6 
> >> altogether in the kernel, but this may not be what you want to achieve.
> >> 
> >> Alternatively, have a look with modinfo in the module options in the unlikely 
> >> chance that the module has some option which disables IPv6 functionality.
> >
> > You may be able to use the feature of modprobe that executes a command
> > when the module loads and that way disable the ipv6 interface.  I have
> > not tried this myself.
> 
> Hello Covici,
> Yes, there's a rule named "install <modulename> [command..]" in
> modprobe, but aren't they only applied to modprobe itself? I mean, in my
> case the ipv6 and tg3 is loaded automatically(maybe by udev?), not by
> running "modprobe ipv6". is this kind of module loading also affected by
> modprobe rule(in /etc/modprobe.d/*.conf)?

I think so, as I use it for my soundcard modules which udev loads.

-- 
Your life is like a penny.  You're going to lose it.  The question is:
How do
you spend it?

         John Covici
         covici@ccs.covici.com