Thanks Christopher, but i think i express myself in an inexact way. Bad english, you know. When i say " hosts playing the role of routers " i wish to mean "uml guests playing the role of routers". In that way i can build more varied topologies, involving more routers. I think it is an one item more than just use the host as a router. Thanks for the information about the tun/tap connection schema. It will be used completely.
Mr Jeff, yes, ppp as the transport for packets between guests UML (playing the role of routers) and between UML guest and the host. In general terms, every time a router (uml as router or host as router) wish to communicate (exchange packets) with another router, he will does that using ppp as link layer protocol. Its a way the make the things to seem more like a real network, using virtual machines. Thanks you all. Regards Haywood/Ernani 2007/6/14, Christopher Marshall <[EMAIL PROTECTED]>: > Haywood: > > The simplest way to do that (have a host act like a router between guests) > would be to use ethertap devices. Each guest would talk to to the host > through a different tap device and the guests would each use eth0 on their > side. > > That's just as if you had the host as a physical host with multiple ethernet > ports and each guest plugged into a separate ethernet port on the host. A > more textbook router setup than that is hard to come by ;-) > > The commands to create a setup like that look like this: > > (as root) > modprobe tun > chmod 666 /dev/net/tun > tunctl -u umluser -t tap1 > tunctl -u umluser -t tap2 > tunctl -u umluser -t tap3 > > (as umluser) > linux ... eth0=tuntap,tap1 ... > linux ... eth0=tuntap,tap2 ... > linux ... eth0=tuntap,tap3 ... > > At this point you need a way to run ifconfig on the guests: > > uml linux guest 1: > ifconfig eth0 10.0.1.2 netmask 255.255.255.0 up > route add default gw 10.0.1.1 > > uml linux guest 2: > ifconfig eth0 10.0.2.2 netmask 255.255.255.0 up > route add default gw 10.0.2.1 > > uml linux guest 3: > ifconfig eth0 10.0.3.2 netmask 255.255.255.0 up > route add default gw 10.0.3.1 > > Then, on the host: > ifconfig tap1 10.0.1.1 netmask 255.255.255.0 up > ifconfig tap2 10.0.2.1 netmask 255.255.255.0 up > ifconfig tap3 10.0.3.1 netmask 255.255.255.0 up > > If you have ip_forwarding enabled on the host, the host and guests should > all be able to ping each other. > > It's certainly possible to use pppd with hosts and guests but it is more > complicated than the above. Especially if your end goal is to use uml as a > test bed to experiment with routing scenarios. > > Automating the above with a script so you can easily scale the scenario is, > of course, harder, but only as a scripting exercise. The uml mechanics are > all contained in the above exmaple. > > Chris Marshall > > Haywood Floyd <[EMAIL PROTECTED]> wrote: > I have the same question. > > I am writing scripts to building an uml based virtual tcp/ip network > to my students. > I wish have hosts playing the role of routers communicating with each > other using ppp. > It is possible ? > > Regards > Ernani > > 2007/6/14, Mark : > > > > I've just started with UML and got Jeff's book (great!!!) > > > > My question is I've looked around, but don't understand why (page 54) says > > that UML doesn't support PPP. Is pppd the problem and can I just use > > something like slirp? (I did find a debian package with UML and slirp). > > > > Any help would be appreciated. > > > > thanks, > > > > Mark > > > > > ------------------------------------------------------------------------- > > This SF.net email is sponsored by DB2 Express > > Download DB2 Express C - the FREE version of DB2 express and take > > control of your XML. No limits. Just data. Click to get it now. > > http://sourceforge.net/powerbar/db2/ > > _______________________________________________ > > User-mode-linux-user mailing list > > User-mode-linux-user@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user > > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > User-mode-linux-user mailing list > User-mode-linux-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user > > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user
