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Mani090's avatar
Mani090
Icon for Nimbostratus rankNimbostratus
Jun 11, 2024

Pool & members showing up in active LB but in standby it is showing down.

I am seeing one pool & its pool member is showing up on active load balancer but on standby it is showing down. Both devices are in sync. On standby pool, session monitor is not showing. Is this some configuration issue or issue is from server end

 

 

tmos)# list ltm pool ent-abc-ghaw-389_pool
ltm pool ent-abc-ghaw-389_pool {
    members {
        10.140.10.14:ldap {
            address 10.140.10.14
            session monitor-enabled
            state up
        }
        10.142.102.37:ldap {
            address 10.142.102.37
            session monitor-enabled
            state up
        }
        10.142.102.47:ldap {
            address 10.142.102.47
            session monitor-enabled
            state up
        }
    }
    monitor tcp
}
====================

session monitor is not showing. This is config on standby device

mos)# list ltm pool ent-abc-ghaw-389_pool
ltm pool ent-abc-ghaw-389_pool {
    members {
        10.140.10.14:ldap {
            address 10.140.10.14
            state down
        }
        10.142.102.37:ldap {
            address 10.142.102.37
            state down
        }
        10.142.102.47:ldap {
            address 10.142.102.47
            state down
        }
    }
    monitor tcp
}

1 Reply

  • Hi, 
    This is not a Sync problem or in other words ( HA doesn't Sync Pool members Status ) as the standby unit should do the health monitoring by it's own selfip ( specially the selfip that can reach to servers/pool members ) 
    so in this case you need to do the following: 

    1. use #ip route get <Pool_member_ip> to know which selfip in the standby unit reach/talk to servers.
    2. If you have a Firewall between your Bigip and servers , you need to monitor if the standby selfip sends health monitor packets periodically to servers or not, also you need to check if the firewall allows the access between the standby unit and servers.
    3. Try to perform telnet test on LDAP port and see if you can connect or not.
    4. Take a packet capture for health monitor traffic between Standby selfip and server, Packet capture should show you what is the issue exactly in the standby path to LDAP servers. 
    5. Please check this article , it has more insights for health monitor troubleshooting and a sample Packet capture command: 
      https://my.f5.com/manage/s/article/K12531