Kernel ethernet alias limit

Kernel ethernet alias limit

[Jim Roland]

I seem to remember back in either Kernel 2.0 or 2.2 there was a limit of 256
aliases within the ethX aliasing (eg, eth0, then eth0:0 thru eth0:255).

Has the limit on this been expanded with Kernel 2.4, is it stable and/or
advised?  I have a need to bind more than 256 addresses to a single
interface.  Without installing additional network cards.

Thanks,
Jim Roland, RHCE

Re: Kernel ethernet alias limit

[Luis Garces]

Hi!

Don't know the exact figures, but I was recently able to create more 
than a thousand eth0:X interfaces in a single machine with 2.2.19 
kernels. And it worked perfectly (answer to ping from another host, etc)

Jim Roland wrote:

> I seem to remember back in either Kernel 2.0 or 2.2 there was a limit of 256
> aliases within the ethX aliasing (eg, eth0, then eth0:0 thru eth0:255).
> 
> Has the limit on this been expanded with Kernel 2.4, is it stable and/or
> advised?  I have a need to bind more than 256 addresses to a single
> interface.  Without installing additional network cards.
> 
> Thanks,
> Jim Roland, RHCE
> 
> 
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> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> 


-- 
Luis
****

Re: Kernel ethernet alias limit

[bert hubert]

On Tue, Feb 19, 2002 at 09:39:30AM +0000, Jim Roland wrote:
> I seem to remember back in either Kernel 2.0 or 2.2 there was a limit of 256
> aliases within the ethX aliasing (eg, eth0, then eth0:0 thru eth0:255).
> 
> Has the limit on this been expanded with Kernel 2.4, is it stable and/or
> advised?  I have a need to bind more than 256 addresses to a single
> interface.  Without installing additional network cards.

Use a loopback interface - you can easily bind to a /8 if you want this way.

I think this is documented in the 'ip' documentation in 'iproute2' from
Alexey. It has also been explained on list here.

Regards,

bert

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Re: Kernel ethernet alias limit

[David Lang]

if you use the new ip tools you can alias a large entblock in a single
command, but even with ifconfig you can do a lot (I have one machine with
>1770 ipaddresses assigned via ifconfig with no problem)

David Lang

 On Tue, 19 Feb 2002, bert hubert wrote:

> Date: Tue, 19 Feb 2002 13:11:21 +0100
> From: bert hubert <ahu@ds9a.nl>
> To: Jim Roland <jroland@roland.net>
> Cc: linux-kernel@vger.kernel.org
> Subject: Re: Kernel ethernet alias limit
>
> On Tue, Feb 19, 2002 at 09:39:30AM +0000, Jim Roland wrote:
> > I seem to remember back in either Kernel 2.0 or 2.2 there was a limit of 256
> > aliases within the ethX aliasing (eg, eth0, then eth0:0 thru eth0:255).
> >
> > Has the limit on this been expanded with Kernel 2.4, is it stable and/or
> > advised?  I have a need to bind more than 256 addresses to a single
> > interface.  Without installing additional network cards.
>
> Use a loopback interface - you can easily bind to a /8 if you want this way.
>
> I think this is documented in the 'ip' documentation in 'iproute2' from
> Alexey. It has also been explained on list here.
>
> Regards,
>
> bert
>
> --
> http://www.PowerDNS.com          Versatile DNS Software & Services
> http://www.tk                              the dot in .tk
> Netherlabs BV / Rent-a-Nerd.nl           - Nerd Available -
> Linux Advanced Routing & Traffic Control: http://ds9a.nl/lartc
> -
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>

Re: Kernel ethernet alias limit

[David Ford]

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You don't need dummy ethN:N interfaces.  Use the iproute2 tools, 'ip' 
specifically.

ip link set eth0 down
ip address flush eth0
ip address add 1.2.3.4/24 brd + dev eth0
ip address add 1.2.3.5/25 brd + dev eth0
ip address add ....to your heart's content
ip link set eth0 up
ip route add default via 2.3.8.9 via 5.4.3.2 dev eth0

See the scripts on http://blue-labs.org/ for some examples.

David

Jim Roland wrote:

>I seem to remember back in either Kernel 2.0 or 2.2 there was a limit of 256
>aliases within the ethX aliasing (eg, eth0, then eth0:0 thru eth0:255).
>
>Has the limit on this been expanded with Kernel 2.4, is it stable and/or
>advised?  I have a need to bind more than 256 addresses to a single
>interface.  Without installing additional network cards.
>
>Thanks,
>Jim Roland, RHCE
>
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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>More majordomo info at  http://vger.kernel.org/majordomo-info.html
>Please read the FAQ at  http://www.tux.org/lkml/
>


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