User-mode Linux kernel port

> Basically what I'm looking to do (if possible) is to make each uml look as
> if they are on there own vlan/subnet.  Thanks, back to reading the ebtables
> manual.

Why not go for the simplest solution and just put each guest on its own 
subnet?  Create a tap interface for each guest, and make it a /30 
network:

  tunctl guest0
  ifconfig guest0 192.168.2.1 netmask 255.255.255.252 up

The guest attached to this interface becomes 192.168.2.2, with a default 
route of 192.168.2.1.

Your next tap interface would be 192.168.2.5, and the associated guest 
would be 192.168.2.6.

A /30 subnet allows for 4 IP addresses:

  (1) The "network" address (host part all zeroes)
  (2) Two IP addresses, which we're using for the host tap interface and 
the guest, and
  (3) The broadcast address (host part all ones)

There's an IP calculator here that can help with this sort of thing:

  http://jodies.de/ipcalc

-- Lars

Shaun wrote:
> Things I'm trying to accomplish
> 1. Stop guests from using ips they were not given
> 2. Stop guests from masking there address or mac as somebody else.
> 3. Stop guests from seeing other guests traffic.

Routing would most probably be your friend here.  Each UML gets a /30, 
one IP on the host and one inside the UML.  You can use RFC1918 space 
for this.  If you require the UML instances to have public IP addresses 
simply route them to the private IP and add them as aliases to the 
interface inside the UML session.

David

I have thought about doing this but giving each guest a /30 seams to my like
a waist of ip space.  I could use private addresses like in your example but
my customers will want to see a public ip on there end and not a private ip.
Thanks though.

~Shaun



"Lars Kellogg-Stedman" <lars@...> wrote in message
news:lars-22D9CC.08474122102004@......
> > Basically what I'm looking to do (if possible) is to make each uml look
as
> > if they are on there own vlan/subnet.  Thanks, back to reading the
ebtables
> > manual.
>
> Why not go for the simplest solution and just put each guest on its own
> subnet?  Create a tap interface for each guest, and make it a /30
> network:
>
>   tunctl guest0
>   ifconfig guest0 192.168.2.1 netmask 255.255.255.252 up
>
> The guest attached to this interface becomes 192.168.2.2, with a default
> route of 192.168.2.1.
>
> Your next tap interface would be 192.168.2.5, and the associated guest
> would be 192.168.2.6.
>
> A /30 subnet allows for 4 IP addresses:
>
>   (1) The "network" address (host part all zeroes)
>   (2) Two IP addresses, which we're using for the host tap interface and
> the guest, and
>   (3) The broadcast address (host part all ones)
>
> There's an IP calculator here that can help with this sort of thing:
>
>   http://jodies.de/ipcalc
>
> -- Lars
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
> Use IT products in your business? Tell us what you think of them. Give us
> Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out
more
> http://productguide.itmanagersjournal.com/guidepromo.tmpl

If i can using private to do the internetworking between the host and guest
thats fine, as long as the guest's eth0 when up shows the public ip.

~Shaun

"David Cannings" <lists@...> wrote in message
news:417929C4.9070006@......
> Shaun wrote:
> > Things I'm trying to accomplish
> > 1. Stop guests from using ips they were not given
> > 2. Stop guests from masking there address or mac as somebody else.
> > 3. Stop guests from seeing other guests traffic.
>
> Routing would most probably be your friend here.  Each UML gets a /30,
> one IP on the host and one inside the UML.  You can use RFC1918 space
> for this.  If you require the UML instances to have public IP addresses
> simply route them to the private IP and add them as aliases to the
> interface inside the UML session.
>
> David
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
> Use IT products in your business? Tell us what you think of them. Give us
> Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out
more
> http://productguide.itmanagersjournal.com/guidepromo.tmpl

Shaun wrote:
> If i can using private to do the internetworking between the host and guest
> thats fine, as long as the guest's eth0 when up shows the public ip.

Give it a go, I'm sure it's possible like that.  Unfortunately, I don't 
have any public IP space to test with.  If I get a minute, I'll try it 
with subnets from different RFC1918 space and report back.

Perhaps somebody who already does this could confirm for us?

David