Thanks for the reply. I had skipped the part on how packets are sent out of my switch in the first mail. Currently the switch sends out untagged packets. I tried to change that to tagged when I had tried to sniff the packets. What I wanted was that if i send out tagged packets from my switch I should be able to sniff them on my box. If I used vconfig on my box, wont I be creating a vlan on my box. Then if I use tcpdump I would be seeing packets which have VLAN id assigned by vconfig and not by the switch. Is this correct ? I would be checking on the driver for the NIC. Thanks, Rahul. On Thu, 9 Oct 2003, Thierry ITTY wrote: > you need to check that the nic driver you use is 802.1p/Q capable, or you > need to get an updated version (i did it for the tulip one, it mainly > consists in accepting longer ethernet frames) > > set up your eth0 interface without an ip > > eventually set up vlan interfaces with "vconfig" and physical device eth0, > at least one to check connectivity > > then try "tcpdump -i eth0" or "tcpdump -i eth0 -vlan x" > > this will work as expected if your switch forwards traffic to your machine, > with tagged frames. having defined vlans on your switch doesn't imply that > all frames are tagged. try to define the port on which you want to run > tcpdump as a trunk, this should tag all frames at least to tell about their > originating vlan > > hth > > > A 12:24 08/10/2003 -0400, vous avez écrit : > >Hi, > > > >I am trying to sniff for VLAN packets on a redhat 9 box. I have a network > >in which I am using the HP Pro Curve 2500 switches. I have configured my > >VLANs on these switches. I have tried the following > > > >On a redhat 9 box which is connected to a VLAN on the switch, I ran > >tcpdump -vlan. However I did not get any packets. The NIC that is > >connected to the VLAN is an Intel EtherExpress/100. The driver installed > >is e100. > > > >Can someone plz give me some insight on how to collect the VLAN packets. > >What am I missing here ? > > > >Thanks, > >Rahul. > > > > > >-- > >redhat-list mailing list > >unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > >https://www.redhat.com/mailman/listinfo/redhat-list > > > > > > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
