CARP and FreeBSD 6.3 (fwd)

[Rakhesh Sasidharan]

(Hi! I had sent this to freebsd-questions first. Didnt get a response, so 
sending it to freebsd-pf. Its a CARP question.)

> Hi,
> 
> I have two machines. Each have two interfaces, xl0 and fxp0. And each have 
> two carp interfaces -- carp1 (xl0 of both) and carp2 (fxp0 of both). One of 
> the machines is master, the other is backup.
> 
> I also have the following sysctl set: net.inet.carp.preempt -> 1
> 
> My understanding is that if I down one of the interfaces on the master 
> machine (say ''ifconfig xl0 down''), then both carp interfaces on the master 
> will be marked as down. And the backup will become the new master. Later, 
> when the interface is marked up (''ifconfig xl0 up''), the old master will 
> resume control. This is my understanding and that's how things were till 
> yesterday (when I was on FreeBSD 6.2/i386 with both machines).
> 
> Today morning I upgraded both machines to FreeBSD 6.3 and that does not seem 
> to be the case any more.
> 
> Now, on the master machine when I down the xl0 interface, only carp1 (the 
> group containing xl0) goes into init state (and the other machine's carp1 
> interface becomes the new master). Ditto for fxp0 and carp2. So in essence, 
> the net.inet.carp.preempt=1 sysctl does not seem to be working as expected 
> which is unlike how things were in FreeBSD 6.2.
> 
> Has something changed with regards to carp between FreeBSD 6.2 and 6.3? Any 
> one else encountering a similar problem?

I happened to reboot the machines now while sitting at the console. And I 
noticed that the master machine emits an error like ''carp2: incorrect hash'' 
while booting up. Checking the console logs showed me that the errors have been 
appearing ever since I upgraded the machine. Most of the times it was to do 
with carp2, once it was to do with carp1.

Here's the relevant bits of my rc.conf file from the master machine.

---8<--
ifconfig_fxp0="inet 192.168.10.10 netmask 255.255.255.0 polling"
ifconfig_fxp0_alias0="inet 192.168.10.11 netmask 255.255.255.255"

ifconfig_xl0="inet 192.168.20.20 netmask 255.255.255.0 polling"

cloned_interfaces="carp1 carp2"
ifconfig_carp1="vhid 1 pass password advskew 0 192.168.10.2 netmask 
255.255.255.0"
ifconfig_carp2_alias0="vhid 2 pass password advskew 0 192.168.20.1 netmask 
255.255.255.0"
ifconfig_carp2_alias1="vhid 2 pass password advskew 0 192.168.20.2 netmask 
255.255.255.0"
---8<--

Its the same on the backup machine, except for the different IPs for fxp0 and 
xl0.

Thanks,
Rakhesh

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