On 05/08/2010 05:38 PM, Jussi Hirvi wrote:
> How can I turn stp on? In my /etc/xen/scripts/xen-network-common.sh
> there is a section:
>
> # Don't create the bridge if it already exists.
> if [ ! -e "/sys/class/net/${bridge}/bridge" ]; then
> brctl addbr ${bridge}
> brctl stp ${bridge} off
> brctl setfd ${bridge} 0
> sysctl -w "net.bridge.bridge-nf-call-arptables=0"
> sysctl -w "net.bridge.bridge-nf-call-ip6tables=0"
> sysctl -w "net.bridge.bridge-nf-call-iptables=0"
> ip link set ${bridge} arp off
> ip link set ${bridge} multicast off
> fi
>
> Is if safe to turn stp "on" there (instead of "off"? (Requires xend
> restart at least, I suppose.) Or is there a better way to turn stp on
> permanently?
STP is safe to turn on, but there is a small start up and tiny
performance hit - that's why its off by default. All the bridges on
your network have to establish relationships with each other, which can
take 10-15 seconds depending on you network. Also, its not just the
bridges on that box that you have to worry about: any other bridges on
other boxes that are on the same network also need STP turned on. Your
old Fedora box may be a potential culprit.
I've never used Xen, so I can't give any firm advice.
That looks like the place where the bridge is created, so at a guess,
that's where you want to turn it on. Not to sure about turning ARP or
MULTICAST off though -- that might interfere with STP.
> The box has 2 physical if cards, and both of them are used for bridges
> (xenbr0 and xenbr1).
Yeah. Thinking you definitely need STP. You can turn it on temporarily
with
brctl stp xenbr0 on
brctl stp xenbr1 on
wait a few seconds and run
brctrl showstp xenbr0
to see what's going on, and also see if it fixes your problem.
Hope this helps
Kal