On Fri, 12 May 2017 08:33:57 +0100 (BST), Stephen Borrill wrote:
xennet0: flags=8963<UP,BROADCAST,NOTRAILERS,RUNNING,PROMISC,SIMPLEX>
xennet0: flags=8963<MULTICAST> mtu 1500
capabilities=2800<TCP4CSUM_Tx,UDP4CSUM_Tx>
enabled=0
ec_capabilities=1<VLAN_MTU>
ec_enabled=0
address: d6:41:19:58:cc:d5
inet6 fe80::d441:19ff:fe58:ccd5%xennet0 prefixlen 64 scopeid 0x2
carp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
capabilities=2800<TCP4CSUM_Tx,UDP4CSUM_Tx>
enabled=0
carp: MASTER carpdev xennet0 vhid 1 advbase 1 advskew 0
address: 00:00:5e:00:01:01
inet 192.168.1.88 netmask 0xffffff00 broadcast 192.168.1.255
If I configure an IP address directly on xennet0 it works.
My understanding is that, behind a system of smoke and mirrors, carp
will add the primary address of a set of redundant machines in a subnet
as an alias to the active machine's interface. This appears to require
that the interface is configured. I have not checked whether you could
get away with rfc1918 addresses as primary addresses on the interfaces;
otherwise, it's (1 + # of machines) ip addresses per subnet.