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Chen_Tat_93126's avatar
Chen_Tat_93126
Icon for Nimbostratus rankNimbostratus
Jul 12, 2011

Network Failover Question

Hi,

 

 

I have 2 LTMs in HA mode where only the Network Failover is activated, without Hardware Failover due to distance constraint.

 

 

 

When I shut down or unplugged the internal VLAN connection from the active system, its state remains as 'active' did not went to 'standby', and the standby system's state went to 'active', and hence, I have 2 active systems instead.

 

 

 

Something is wrong here, I am supposed to have the second unit change its state to 'active' and the current 'active' unit change its that to 'standby'.

 

 

 

Any one can advise me what is wrong here? Did I missed out any configuration? Pls help me, thanks!

 

 

 

My existing network failover configuration for the 2 units are as follow:

 

 

 

Unit 1:

 

Peer management address: 192.168.1.1

 

Configuration Identifier: netfail1

 

Local Address: 172.16.1.1

 

Remote Address: 172.16.1.2

 

 

 

Unit 2:

 

Peer management address: 192.168.1.2

 

Configuration Identifier: netfail2

 

Local Address: 172.16.1.2

 

Remote Address: 172.16.1.1

 

 

 

 

 

 

 

 

 

 

 

 

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  • Moz_58995's avatar
    Moz_58995
    Icon for Nimbostratus rankNimbostratus
    Jul 12, 2011
    Hi Chen,

     

     

    That behaviour actually sounds right to me (somebody may correct me). Just because the active device can’t see its mate doesn’t mean it goes into ‘standby’, and it shouldn’t matter because all traffic should go to the standby, now ‘active’ as the link to the active is down.

     

     

    Whereas if you simulate a failover by rebooting the active device (and the redundancy preferences on both devices are set to none), it will come back up as standby.

     

     

    Hope that helps.

     

     

    Matt
  • Przemek_110000's avatar
    Przemek_110000
    Icon for Nimbostratus rankNimbostratus
    Jul 12, 2011
    Chen is right. In this case both units go active.

     

     

    recently I've tested it and there is very nice functionality like vlan failsafe. You should consider it as well.

     

    Additionally to your HA interface it is good to turn it on on all vlans. In other case if your external interface goes down and FO is enabled only on internal vlan 1st unit is unresponsive to external request and 2nd unit is in standby state.

     

     

    regards
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    Jul 12, 2011
    You could also look into HA groups in v10 for implementing more advanced failover logic:

     

     

    Configuring HA groups

     

    http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos_management_guide_10_1/tmos_high_avail.html?sr=154641061026652

     

     

    Aaron
  • Chen_Tat_93126's avatar
    Chen_Tat_93126
    Icon for Nimbostratus rankNimbostratus
    Jul 13, 2011
    Hi all experts, thanks for you help and explanation, I will be trying out the VLAN failsafe and HA groups features.