VLAN issues

Matthew Dillon dillon at apollo.backplane.com
Sun Mar 25 09:39:19 PDT 2007


    One thing I noticed about this patch is that there might be a logic
    error when clearing vlan flags.

    Lets say you have four vlan's, and you turn on promiscuous mode on two
    of them.  This propogates to the parent.   But now what happens if you
    turn off promiscuous mode on one of them?  Will it turn off promiscuous
    mode in the parent even though there is still one vlan interface left
    with it turned on?

    Also, if someone turns on promisc mode on the parent, and then turns it
    on for a vlan interface, then turns it off for a vlan interface, will
    it turn off the mode on the parent?  We wouldn't want it to.

    Another example... bridging turns on promiscuous mode.  But if an
    interface is bridged, and someone tcpdump's a vlan under that interface,
    then stops the tcpdump, will that turn off the interface's promiscuous
    mode?  Again we wouldn't want it to.

    We might have to track promiscuous mode or have additional IFF flags
    for bridging and vlan inheritance that also independantly turn on
    promisc mode (so it wouldn't be turned off unless all the related
    flags are clear).  Then tcpdump wouldn't blow things up.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>

:On 3/25/07, Gergo Szakal <bastyaelvtars at gmail.com> wrote:
:> Ok, continuing this old discussion:
:> http://tinyurl.com/2a7qda
:>
:> Installed 1.8.0, applied the patch, rebuilt GENERIC and rebooted. Loading if_vlan.ko and if_bridge.ko from loader.conf.
:>
:> Well, this is my rc.conf file:
:>
:> ------------------------------------------------------------------------------
:> cloned_interfaces="bridge0 vlan0 vlan1 vlan2 vlan3"
:> ifconfig_vlan0="vlan 11 vlandev xl0 up"
:> ifconfig_vlan1="vlan 12 vlandev xl0 up"
:> ifconfig_vlan2="vlan 11 vlandev xl1 up"
:> ifconfig_vlan3="vlan 12 vlandev xl1 up"
:> ifconfig_xl0="up"
:> ifconfig_xl1="up"
:> ifconfig_bridge0="addm vlan0 addm vlan1 addm vlan2 addm vlan3 up"
:> ------------------------------------------------------------------------------
:>
:> My issues:
:> 1) No pseudo-interfaces get up. I have to "ifconfig xxxn up" them manually.
:
:It is a bug in vlan code: when set up vlan config, vlan's if_flags
:will be overwritten :(
:
:> 2) VLAN interfaces do not get added as bridge0 members.
:
:vlan does not support promisc mode in current code base
:
:> Any ideas?
:
:Would you like to test following patch?
:http://leaf.dragonflybsd.org/~sephe/vlan.diff
:
:Best Regards,
:sephe
:
:-- 
:Live Free or Die






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