[Pacemaker] [SOLVED] Re: Multicast corosync packets and default route

[Daniel Dehennin]

Daniel Dehennin <daniel.dehennin at baby-gnu.org> writes:

> Daniel Dehennin <daniel.dehennin at baby-gnu.org> writes:
>
>> Hello,
>>
>
> [...]
>
>> I only manage to have my VM as corosync member like others when default
>> the route is on the same interface as my multicast traffic.

[...]


Using tcpdump I found the difference between single card VM and multicard VM.

When using multiple cards, I need to force the IGMP version since my
physical switches does not support IGMPv3.

It looks like the kernel uses IGMPv3 to register any local IP addresses
to the multicast group.


Single card VM:

    No.  Time      Source           Destination  Protocol Info
      2  0.000985  192.168.231.110  226.94.1.1   IGMPv2   Membership Report group 226.94.1.1

    Frame 2: 46 bytes on wire (368 bits), 46 bytes captured (368 bits)
    Ethernet II, Src: RealtekU_03:6d:2d (52:54:00:03:6d:2d), Dst: IPv4mcast_5e:01:01 (01:00:5e:5e:01:01)
    Internet Protocol Version 4, Src: 192.168.231.110 (192.168.231.110), Dst: 226.94.1.1 (226.94.1.1)
    Internet Group Management Protocol
        [IGMP Version: 2]
        Type: Membership Report (0x16)
        Max Resp Time: 0,0 sec (0x00)
        Header checksum: 0x06a0 [correct]
        Multicast Address: 226.94.1.1 (226.94.1.1)

Multicard VM:

    No.  Time      Source           Destination  Protocol Info
      2  0.004419  192.168.231.111  224.0.0.22   IGMPv3   Membership Report / Join group 226.94.1.1 for any sources

    Frame 2: 54 bytes on wire (432 bits), 54 bytes captured (432 bits)
    Ethernet II, Src: RealtekU_dc:b6:92 (52:54:00:dc:b6:92), Dst: IPv4mcast_16 (01:00:5e:00:00:16)
    Internet Protocol Version 4, Src: 192.168.231.111 (192.168.231.111), Dst: 224.0.0.22 (224.0.0.22)
    Internet Group Management Protocol
        [IGMP Version: 3]
        Type: Membership Report (0x22)
        Header checksum: 0xf69e [correct]
        Num Group Records: 1
        Group Record : 226.94.1.1  Change To Exclude Mode
            Record Type: Change To Exclude Mode (4)
    	Aux Data Len: 0
    	Num Src: 0
    	Multicast Address: 226.94.1.1 (226.94.1.1)

So I force the IGMP version for all interfaces with the following:

    sysctl -w net.ipv4.conf.all.force_igmp_version=2

Now my dual card VM is part of the ring:

    root at nebula3:~# corosync-quorumtool
    Quorum information
    ------------------
    Date:             Fri Nov  7 16:32:34 2014
    Quorum provider:  corosync_votequorum
    Nodes:            5
    Node ID:          1084811080
    Ring ID:          20624
    Quorate:          Yes
    
    Votequorum information
    ----------------------
    Expected votes:   5
    Highest expected: 5
    Total votes:      5
    Quorum:           3
    Flags:            Quorate WaitForAll LastManStanding
    
    Membership information
    ----------------------
        Nodeid      Votes Name
        1084811078          1 nebula1.eole.lan
        1084811079          1 nebula2.eole.lan
        1084811080          1 nebula3.eole.lan (local)
        1084811118          1 quorum.eole.lan
        1084811119          1 one-frontend.eole.lan

-- 
Daniel Dehennin
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