When the system with the carp interfaces comes up, a sleep in the
hostname.if file works. An arping might be an optimization of that.
But I'd like carp to react properly to events *outside* the system.
When I unplug/plug a network cable, spanning tree can kick in again on
the switch. *Then* I'd like carp to pause.
Or the example I mentioned earlier when a switch is powered off and on.
I think handling that belongs in the kernel, and not some userland
voodoo (ifstated/cron scripts) to clean it up. :-)
On 4/3/13 3:37 PM, sven falempin wrote:
my 2 cents:
timing is always a problem, maybe you could arping the next hop and then
activate the carp ?
On Wed, Apr 3, 2013 at 9:34 AM, Stuart Henderson <s...@spacehopper.org>wrote:
On 2013/04/03 14:54, Camiel Dobbelaar wrote:
In some cases when a network port comes up, it does not indicate that
the network is ready. But on linkup, carp(4) will try to get out of
the INIT state as soon as possible. And because all is quiet it will
decide to become master.
This then leads to master-master situations.
Here are two examples when this can happen, there are probably more:
(1) spanning tree may be in effect, and not yet forwarding
(2) a powering-up or rebooting switch that activates its ports
immediately, but does not forward anything while not completely up
yet (this may be an openbsd bridge too)
I wonder if carp(4) needs an extra knob (*shudder*) to pause in the
INIT state while the rest of the network gets ready after a linkup.
I see in the source code there are already two mechanisms/workarounds
that are related, but a pause may be a bit more generic:
- sc_suppress
- sc_delayed_arp
Anyone else observe/fix this by other means? Opinions?
slightly messy, though at least this also applies to the case with
things other than carp which could also have problems: add "!sleep 5"
or something in hostname.if for the physical interface...
