On Tue, 16 Nov 2004 21:02:02 +0100 Harald Sauff <2gr84u@xxxxxxxxx> wrote: > Hello list, > > I'm setting up a virtual network consisting of several UMLs (User Mode > Linux) connected with the virtual bridge. > Communications works quite well between the host and the virtual machines. > > Setup: > 2 UMLs connected via tap-devices to the bridge (tap1,tap2). > The host uses the bridge-device br0 to talk to the clients. > > Now I want to tcpdump the traffic between host and UML1 on virtual machine UML2. > > With the standard-settings UML2 only catches the initial > ARP-broadcasts (but that's the intended behaviour of the > bridge/switch). :-) > > Now I set "brctl setageingtime br0 0", so that the bridge behaves like > a hub (it forgets the MAC-addresses immediately) and broadcasts all > packets on all connected ports. Checking this with "brctl showmacs > br0" shows, that this is working, the MAC-table is always empty. > > BUT: on UML2 (the listening machine) I see only the complete traffic > coming from the host (via br0 into the bridge), but the answers from > UML2 to the host (entering the bridge on tap2) are hidden (only > broadcasts can be seen). > > Why does the broadcasting of all packets only work from the bridge > directly (br0) and not from the connected tap-devices? > > Could this have to do with the fact, that with version 1.0.4 of the > bridge-utils (Debian 3.1, testing) I can't control the GC-time of the > bridge? > > In the mailing-list archive I found a thread, where someone wanted the > bridge to be configured as a hub, but the advice to remove some lines > of code from the bridge-code didn't work for me, the bridge is > unusable after removing the code. > > Can someone give me a hint, how to get the desired behaviour? An > option for switching between hub- and switch-behaviour would be > nice... ;-) > > > thanx in advance, > Harald Sauff What version of kernel. The utilities don't matter much, they only setup the kernel. You could talk to Werner Almesberger about similar stuff in umlsim
