marionnet-dev team mailing list archive

[jean-vincent.loddo@xxxxxxxxxxxxxxxxxxxx]

Hi Simon,

in the original project we had the idea of supporting several Marionnet 
instances on the same host. But this idea was rapidly forgot when we 
have observed the number of concurrent processes running for a single 
instance. So, the design of Marionnet reflects some ideas in this 
direction but the feature isn't completely supported.

> Is there any way to insure that assignment of IP addresses to
> Marionnet hosts will be unique?

Not in the current status of code, even if the patch seems not so hard 
to implement. If you really want, I can plan it in the TODO list, but in 
my opinion there are many critical points to analyse and test to be sure 
that the feature is really implemented. You have found a problem but it 
is probably not the only problem.

However, I believe that there exists a workaround for you, exploiting 
the IPv6 adressing (and routing, because your problem is about routing). 
If you are really interested and not discouraged by my previous speech, 
I can explain this idea in details.

Best regards,
Jean-Vincent Loddo

On Fri, 24 Apr 2015 16:36:23 -0400, Simon Baev wrote:
> Hello,
>
> I am running Marionnet in a classroom environment on LTSP server. Our
> students can run multiple concurrent Marionnet sessions to work on
> several concurrently running projects.
>
> Each Marionnet host creates a TAP interface on the server side with 
> IP
> 172.23.0.254 which at the other end is connected to Marionnet host. 
> My
> intend was to make possible to ssh to Marionnet hosts  from Ubuntu
> terminal because it is MORE CONVENIENT compared to XTERM which is
> bound by default to remote host(s).
>
> I created and started two projects,  then, on every Marionnet host I
> activated SSH service allowing root login. The problem I'm facing is
> inability to determine which IP address to SSH from HOST (Ubuntu) to
> reach particular Marionnet hosts. 
>
> I ran NETSTAT -RN  to find out association between particular TAP
> interfaces and their matching remote IP a ddresses, here is a snippet
> of exampled output:
>
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags   MSS
> Window  irtt Iface
> 0.0.0.0         168.18.104.33   0.0.0.0         UG      
>  0 0          0 eth0
> 10.0.16.0       0.0.0.0         255.255.255.0   U        
> 0 0          0 eth1
> 168.18.104.32   0.0.0.0         255.255.255.240 U         0 0
>          0 eth0
> 172.23.0.1      0.0.0.0         255.255.255.255 UH        0
> 0 � �        0 tap143133
> 172.23.0.1      0.0.0.0         255.255.255.255 UH        0
> 0          0 tap144015
> 172.23.0.2      0.0.0.0         255.255.255.255 UH        0
> 0          0 tap563104
> 172.23.0.2      0.0.0.0         255.255.255.255 UH        0
> 0          0 tap571651
> 172.23.0.3      0.0.0.0         255.255.255.255 UH        0
> 0          0 tap154589
>
> I came up with a small script that looks at /TMP/MARIONNET* files and
> determines IP addresses that particular user runs:
>
> #!/ bin/bash
> if [ $# -lt 1 ]; then
>
>    echo "Need one parameter -- name of the MarionNet project" 1>&2
>    exit 1
> fi
> mhome=$(find /tmp -name "marionnet*" -user $(whoami) 2> /dev/null)
>
> if [ ! -d "$mhome/$1" ]; then
>
>    echo "Project '$1' doesn't exist" 1>&2
>    exit 2
> fi
> for hostinfo in $mhome/$1/hostfs/*; do
>
>    awk -F"'" '/ip42|hostname/{print $2}' "$hostinfo/boot_parameters"
> done | paste -s -d",n"
>  
> this script prints something similar to:
>
> 172.23.0.1,R1
> 172.23.0.2,m1
> 172.23.0.3,m2
>
> for one project, and
> < br>
>
> 172.23.0.1,mt1
> 172.23.0.2,mt2
>
> for another. 
>
> I can see that two different projects have 172.23.0.1 associated with
> their first internal host, i.e. with R1 on one project and with MT1 
> on
> another project. When I SSH to 172.23.0.1 from Ubuntu host I'm 
> getting
> to R1. Is there any way to insure that assignment of IP addresses to
> Marionnet hosts will be unique?
>
> Thank you.
>
> --
> Simon