Thanks Roman. I was starting to suspect this. I guess the same applies to other modules that expect IP packets.
Next question : when you are done processing the raw IP, how do you put an ethernet header back on, prior to the Queue() -> ToDevice() combination? cheers On 10/25/07, Roman Chertov <[EMAIL PROTECTED]> wrote: > Daniel McBrearty wrote: > > Hi > > > > Have been playing around with this great piece of software for a few > > days. Had some success with it, but one thing seems to cause some > > trouble. > > > > I seem not to be understanding something basic about how many elements > > handle IP headers. > > > > For instance, if I have a config like this : > > > > ipc IPClassifier( ip proto udp, - ); > > FromDevice( etho, PROMISC true ) -> ipc; > > ipc[0] -> Queue() -> ToDevice( eth1 ); > > ipc[1] -> Discard(); > > > > Now, I run this in user mode, and send it a few hundred RTP packets. > > It core dumps. The core dump goes if I remove ipc. > > It core dumps because it is trying to read IP headers from where > Ethernet headers are. You need to use a classifier first and then strip > 14 bytes before you can send packets to the IPClassifier. > > Roman > > > > > Other problems I have had have been trying to use SetIPAddress( > > 1.2.3.4, dst ) in such a config, but the ip appears unchanged in > > wireshark. > > > > Do these IP based elements expect the ethernet header to be stripped > > off, or explicitly told the position relative to the start of an > > ethernet header? I seem to remember seeing something like this when I > > started reading the docs ... but I can't find that now. > > > > thanks > > > > Daniel > > _______________________________________________ > > click mailing list > > click@amsterdam.lcs.mit.edu > > https://amsterdam.lcs.mit.edu/mailman/listinfo/click > > > -- Daniel McBrearty email : danielmcbrearty at gmail.com http://www.engoi.com http://danmcb.vox.com http://danmcb.blogger.com find me on linkedin and facebook BTW : 0873928131 _______________________________________________ click mailing list click@amsterdam.lcs.mit.edu https://amsterdam.lcs.mit.edu/mailman/listinfo/click
