[ClusterLabs] Antw: Regarding IP tables and IP Address clone

Somanath Jeeva somanath.jeeva at ericsson.com
Wed Dec 30 15:56:58 CET 2015


>From: Michael Schwartzkopff [mailto:ms at sys4.de] 
>Sent: Wednesday, December 30, 2015 8:09 PM
>To: Cluster Labs - All topics related to open-source clustering welcomed
>Subject: Re: [ClusterLabs] Antw: Regarding IP tables and IP Address clone

Am Mittwoch, 30. Dezember 2015, 13:54:40 schrieb Somanath Jeeva:
> >>>> Somanath Jeeva <somanath.jeeva at 
> >>>> ericsson.com<http://clusterlabs.org/mailman/listinfo/users>> 
> >>>> schrieb am 30.12.2015 um 11:34 in>
> >Nachricht <4F5E5141ED95FF45B3128F3C7B1B2A6721ABFE13 at
eusaamb109.ericsson.se<http://clusterlabs.org/mailman/listinfo/users>>:
> >> On 12/22/2015 08:09 AM, Somanath Jeeva wrote:
> >>> Hi
> >>> 
> >>> I am trying to use ip loadbalancing using cloning feature in pacemaker.
> >>> but
> >> 
> >> After 15 min the virtual ip becomes unreachable. Below is the 
> >> pacemaker
> >> 
> >> cluster config
> >> 
> >>>  # pcs status
> >>> 
> >>> Cluster name: DES
> >>> 
> >>> Last updated: Tue Dec 22 08:57:55 2015
> >>> 
> >>> Last change: Tue Dec 22 08:10:22 2015
> >>> 
> >>> Stack: cman
> >>> 
> >>> Current DC: node-01 - partition with quorum
> >>> 
> >>> Version: 1.1.11-97629de
> >>> 
> >>> 2 Nodes configured
> >>> 
> >>> 2 Resources configured
> >>> 
> >>> 
> >>> 
> >>> 
> >>> 
> >>> Online: [ node-01 node-02 ]
> >>> 
> >>> Full list of resources:
> >>>  Clone Set: ClusterIP-clone [ClusterIP] (unique)
> >>>  
> >>>      ClusterIP:0        (ocf::heartbeat:IPaddr2):       Started node-01
> >>>      
> >>>      ClusterIP:1        (ocf::heartbeat:IPaddr2):       Started node-02
> >>> 
> >>> #pcs config
> >>> 
> >>> Cluster Name: DES
> >>> 
> >>> Corosync Nodes:
> >>>   node-01 node-02
> >>> 
> >>> Pacemaker Nodes:
> >>> 
> >>> node-01 node-02
> >>> 
> >>> Resources:
> >>>  Clone: ClusterIP-clone
> >>>  
> >>>   Meta Attrs: clone-max=2 clone-node-max=2 globally-unique=true
> >>>   
> >>>   Resource: ClusterIP (class=ocf provider=heartbeat type=IPaddr2)
> >>>   
> >>>    Attributes: ip=10.61.150.55 cidr_netmask=23 
> >>> clusterip_hash=sourceip
> >>>    
> >>>    Operations: start interval=0s timeout=20s
> >>>    (ClusterIP-start-timeout-20s)
> >>>    
> >>>                stop interval=0s timeout=20s 
> >>> (ClusterIP-stop-timeout-20s)
> >>>                
> >>>                monitor interval=5s (ClusterIP-monitor-interval-5s)
> >>> 
> >>> Stonith Devices:
> >>> 
> >>> Fencing Levels:
> >>> 
> >>> 
> >>> 
> >>> Location Constraints:
> >>> 
> >>> Ordering Constraints:
> >>> 
> >>> Colocation Constraints:
> >>> 
> >>> Cluster Properties:
> >>>  cluster-infrastructure: cman
> >>>  
> >>>  cluster-recheck-interval: 0
> >>>  
> >>>  dc-version: 1.1.11-97629de
> >>>  
> >>>  stonith-enabled: false
> >>> 
> >>> Pacemaker and Corosync version:
> >>> 
> >>> Pacemaker - 1.1.12-4
> >>> 
> >>> Corosync  - 1.4.7
> >>> 
> >>> 
> >>> 
> >>> 
> >>> 
> >>> Is the issue due to configuration error or firewall issue.
> >>> 
> >>> 
> >>> 
> >>> 
> >>> 
> >>> With Regards
> >>> 
> >>> Somanath Thilak J
> >>> 
> >>> 
> >>> 
> >>> Hi Somanath,
> >> 
> >> The configuration looks fine (aside from fencing not being 
> >> configured),
> >> 
> >> so I'd suspect a network issue.
> >> 
> >> 
> >> 
> >> The IPaddr2 cloning relies on multicast MAC addresses (at the 
> >> Ethernet
> >> 
> >> level, not multicast IP), and many switches have issues with that. 
> >> Make
> >> 
> >> sure your switch supports multicast MAC (and if necessary, has it
> >> 
> >> enabled on the relevant ports).
> >> 
> >> 
> >> 
> >> Some people have found it necessary to add a static ARP entry for 
> >> the
> >> 
> >> cluster IP/MAC in their firewall and/or switch.
> >> 
> >> 
> >> 
> >> Hi ,
> >> 
> >> 
> >> 
> >> It seems that the switches have multicast support enabled. Any idea 
> >> on how
> >> 
> >> to trouble shoot the issue. I also tried adding the Multicast MAC 
> >> to the ip
> >> 
> >> neigh tables. Still the Virtual IP goes down in 15 min or so.
> >
> >Did you try a "watch arp -vn" on your nodes to watch for changes (if 
> >you only have a few connections)?
> I could not see my virtual ip in the arp -vn command output. Only if 
> ass the static arp entry I can see the Virtual IP in the command o/p. 
> I see the virtual ip and MAC only in iptables,ip addr,ip maddr 
> commands
> 
> 
> 
> # service iptables status
> 
> Table: filter
> 
> Chain INPUT (policy ACCEPT)
> 
> num  target     prot opt source               destination
> 
> 1    CLUSTERIP  all  --  0.0.0.0/0            10.61.150.55        CLUSTERIP
> hashmode=sourceip clustermac=51:33:83:16:0A:BF total_nodes=2 
> local_node=2
> hash_init=0
> 
> 2    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
> 
> 
> 
> Chain FORWARD (policy ACCEPT)
> 
> num  target     prot opt source               destination
> 
> 
> 
> Chain OUTPUT (policy ACCEPT)
> 
> num  target     prot opt source               destination
> 
> 1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
> 
> 
> 
> # ip addr show bond0
> 
> 6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc 
> noqueue state UP
> 
>     link/ether 00:0c:29:32:8d:b9 brd ff:ff:ff:ff:ff:ff
> 
>     inet 10.61.150.212/23 brd 10.61.151.255 scope global bond0
> 
>     inet 10.61.150.55/23 brd 10.61.151.255 scope global secondary 
> bond0
> 
>     inet6 fe80::20c:29ff:fe32:8db9/64 scope link tentative dadfailed
> 
>        valid_lft forever preferred_lft forever
> 
> 
> 
> # ip maddr show bond0
> 
> 6:      bond0
> 
>         link  51:33:83:16:0a:bf
> 
>         link  01:00:5e:01:01:02
> 
>         link  33:33:ff:32:8d:b9
> 
>         link  33:33:00:00:00:01
> 
>         link  33:33:00:00:02:02
> 
>         link  33:33:00:75:00:75
> 
>         link  01:00:5e:00:00:01
> 
>         inet  224.1.1.2
> 
>         inet  224.0.0.1
> 
>         inet6 ff02::1:ff32:8db9
> 
>         inet6 ff0e::75:75
> 
>         inet6 ff02::202
> 
>         inet6 ff02::1
> 
> >> Regards
> >> 
> >> Somanath Thilak J

>Hi,

>instead of wild geussing, you should do a more systematic research.

>- If your VIP becomes not accessialbe any more, what are the ARP reuests on the network? tcpdump is your friend ;-)

I already the tcp dump during both the times the availability was there and not  there.

Here is the output I got

When Reachable:

 08:39:24.639101 IP (tos 0x0, ttl 64, id 11469, offset 0, flags [DF], proto TCP (6), length 100)
    10.61.150.55.ssh > 136.225.198.11.41071: Flags [P.], cksum 0xefb7 (incorrect -> 0x7599), seq 3590:3638, ack 2486, win 175, options [nop,nop,TS val 2343972672 ecr 2807901513], length 48
08:39:24.639692 IP (tos 0x10, ttl 61, id 4485, offset 0, flags [DF], proto TCP (6), length 500)
    136.225.198.11.41071 > 10.61.150.55.ssh: Flags [P.], cksum 0xd1c3 (correct), seq 2486:2934, ack 3638, win 175, options [nop,nop,TS val 2807901735 ecr 2343972672], length 448
08:39:24.639728 IP (tos 0x0, ttl 64, id 11470, offset 0, flags [DF], proto TCP (6), length 52)

When not reachable :

08:46:53.936447 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 10.61.150.55 tell 10.61.150.2, length 46
08:46:53.936474 ARP, Ethernet (len 6), IPv4 (len 4), Reply 10.61.150.55 is-at 51:33:83:16:0a:bf (oui Unknown), length 28

>- As I told you  before, check the mac address tables of your switch. Is it OK?

I check with the systems team. They said MAC multicasting is enabled. Also do I have to add anything in the switch side manually. 

>- Check the arp tables of the sending host / router. Is there an entry for the VIP? With the correct (multicast!) MAC?


Another point is , I am trying this configuration in a clustered environment and  the said virtual IP is reachable within the cluster always .
But when I ping from outside the cluster it is not reachable after sometime. If I restart the iptables it becomes reachable for some time.

>Mit freundlichen Grüßen,

>Michael Schwartzkopff

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