Hi,
I'm running two FreeBSD 9.1 VMs on a KVM Hypervisor. While this basically works quite well, I can't get uCARP to work. First I thought it must be a multicast issue (because I consider multicast to be black magic), but a quick test shows (I assume) that multicast is working:
On VM 1 I started a multicast server:
And on VM 2 I started a multicast client:
On my KVM hypervisor I can see these packets going through:
As you can see from the iperf output, 445 out of 446 datagrams could be received by VM 1. That's why I assume multicast is basically working.
The problem is that uCARP/VRRP is not working :-( I can see the VRRP advertisements on my KVM hypervisor as well:
... but they never reach the interface of the other FreeBSD VM. I don't think it's a FreeBSD issue, but maybe someone has seen this before and may give some advice how to tweak KVM or possibly iptables to make (u)CARP work. I've already tried pfSense (with native CARP) and it's the same problem.
Thanks
- Frank
I'm running two FreeBSD 9.1 VMs on a KVM Hypervisor. While this basically works quite well, I can't get uCARP to work. First I thought it must be a multicast issue (because I consider multicast to be black magic), but a quick test shows (I assume) that multicast is working:
On VM 1 I started a multicast server:
Code:
vm1# iperf -s -u -B 224.0.67.67 -i 1
------------------------------------------------------------
Server listening on UDP port 5001
Binding to local address 224.0.67.67
Joining multicast group 224.0.67.67
Receiving 1470 byte datagrams
UDP buffer size: 41.1 KByte (default)
------------------------------------------------------------
[ 3] local 224.0.67.67 port 5001 connected with 10.10.10.2 port 65530
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 3] 0.0- 1.0 sec 126 KBytes 1.03 Mbits/sec 0.165 ms 0/ 88 (0%)
[ 3] 1.0- 2.0 sec 126 KBytes 1.03 Mbits/sec 0.163 ms 0/ 88 (0%)
[ 3] 2.0- 3.0 sec 128 KBytes 1.05 Mbits/sec 0.162 ms 0/ 89 (0%)
[ 3] 3.0- 4.0 sec 129 KBytes 1.06 Mbits/sec 0.122 ms 0/ 90 (0%)
[ 3] 4.0- 5.0 sec 128 KBytes 1.05 Mbits/sec 0.174 ms 0/ 89 (0%)
[ 3] 0.0- 5.0 sec 640 KBytes 1.05 Mbits/sec 0.176 ms 0/ 445 (0%)
[ 3] 0.0- 5.0 sec 1 datagrams received out-of-orderAnd on VM 2 I started a multicast client:
Code:
vm2# iperf -c 224.0.67.67 -u --ttl 5 -t 5
------------------------------------------------------------
Client connecting to 224.0.67.67, UDP port 5001
Sending 1470 byte datagrams
Setting multicast TTL to 5
UDP buffer size: 9.00 KByte (default)
------------------------------------------------------------
[ 3] local 10.10.10.2 port 65530 connected with 224.0.67.67 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0- 5.0 sec 640 KBytes 1.05 Mbits/sec
[ 3] Sent 446 datagramsOn my KVM hypervisor I can see these packets going through:
Code:
kvm# tcpdump -i vnet13 -s 1500 -n -X host 224.0.67.67
11:14:58.113280 IP 10.10.10.2.10745 > 224.0.67.67.commplex-link: UDP, length 1470
11:14:58.113457 IP 10.10.10.2.10745 > 224.0.67.67.commplex-link: UDP, length 1470
11:14:58.143342 IP 10.10.10.2.10745 > 224.0.67.67.commplex-link: UDP, length 1470As you can see from the iperf output, 445 out of 446 datagrams could be received by VM 1. That's why I assume multicast is basically working.
The problem is that uCARP/VRRP is not working :-( I can see the VRRP advertisements on my KVM hypervisor as well:
Code:
kvm# tcpdump -i vnet13 -s 1500 -n -X |grep -i vrrp
tcpdump: WARNING: vnet13: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vnet13, link-type EN10MB (Ethernet), capture size 1500 bytes
11:17:46.386437 IP 10.10.10.2 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 0, authtype none, intvl 1s, length 36
11:17:47.353269 IP 10.10.10.2 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 0, authtype none, intvl 1s, length 36
11:17:48.363266 IP 10.10.10.2 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 0, authtype none, intvl 1s, length 36... but they never reach the interface of the other FreeBSD VM. I don't think it's a FreeBSD issue, but maybe someone has seen this before and may give some advice how to tweak KVM or possibly iptables to make (u)CARP work. I've already tried pfSense (with native CARP) and it's the same problem.
Thanks
- Frank
