Re: [Vserver] Re: IP alias limitation

From: Bruno <>
Date: Wed 23 Aug 2006 - 21:22:19 BST
Message-Id: <>

On Wednesday 23 August 2006 22:08, Kathy Kost wrote:
> Nope. Once an alias is created, however which way, the system comes up
> with a "16 alias max" message. Don't recall the actual message. The
> vserver would not restart and I had to remove the interfaces and reboot
> the entire server.
> Kathy
> > Does it help to add ip's with the ip add ... command instead of using
> > ifconfig? Aliases are sooo last millennium.
> >
> >
> > /Benny
The kernel patch has a maximum of IP addresses per network context defined.

Context-association of IP addresses is not optimized, thus many addresses
cause some overhead when checking if incoming packets may be delivered to a
guest. (check if IP is available to a guest)

In addition you have 12 bytes allocated per possible IP address:
 12 * 16 = 192 bytes (even if guest has just 1 IP assigned to it)

For the define limiting the count of IP addresses, see
  include/linux/vserver/network.h (line 11):

@define NB_IPV4ROOT 16

Note that you may need to check what header the userspace tools get compiled

Vserver mailing list
Received on Wed Aug 23 21:22:41 2006

[Next/Previous Months] [Main vserver Project Homepage] [Howto Subscribe/Unsubscribe] [Paul Sladen's vserver stuff]
Generated on Wed 23 Aug 2006 - 21:22:45 BST by hypermail 2.1.8