Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

Kannan_Thalaia1's avatar
Kannan_Thalaia1
Icon for Cirrus rankCirrus
Jun 12, 2020

vCMP Migration Issue

Hi,   Currently we are migrating our physical devices ( in two datacenter) into virtual one (vCMP Guests).   The both DCs are using same VLAN IDs but using different IPs.   For example s...
application delivery
big-ip
LTM
youssef1's avatar
youssef1
Icon for Cumulonimbus rankCumulonimbus
Jun 12, 2020

Hello Kannan,

 

so if I understand correctly, you had 2 physical (one by DC) equipment that you want to replace with one. in this case a virtual device (GUEST VCMP).

 

the configuration of your Physical equipment are like:

  • F5 1 (Datacenter A): VLAN ID 503 - 10.10.188.*
  • F5 2 (Datacenter B): VLAN ID 503 - 10.20.125.*

 

your request is relatively simple; on your HOST (Hypervisor), create your VLAN 503.

Then attach this VLAN to your GUEST

In your Guest you can create 2 SelfIP on the same VLAN on the same Guest:

  • 10.10.188.10
  • 10.20.125.10

 

Let me know if you need more details.

 

regards

 

 

 

  • Kannan_Thalaia1's avatar
    Kannan_Thalaia1
    Icon for Cirrus rankCirrus
    Jun 14, 2020

    Hello Youssef,

     

    Thanks for your update.

     

    In our scenario, the both LTMs are hosted in different datacenter. Each DC has Site-A & Site-B. The LTM is running in one-armed mode, in active/standby mode.

     

    PROD-1 DC: ( VLAN 503, VLAN 504, VLAN 701, LTM uplinks connected to two different nexus switches and bundled together)

    HQBUSXC101(LTM) --> HQBUSXR101(Nexus with VPC) --> Site-A

    HQBUSXC101(LTM) --> HQBUSXR102(Nexus with VPC) --> Site-A

     

    PROD-2 DC: ( VLAN 503, VLAN 504, VLAN 701, LTM uplinks connected to two different nexus switches and bundled together )

    HQBUSXC201(LTM) --> HQBUSXR201(Nexus with VPC) --> Site-A

    HQBUSXC201(LTM) --> HQBUSXR202(Nexus with VPC) --> Site-A

     

    Now we need to merge the PROD-1 & PROD-2 Site-A LTMs , 2 physical chassis into 1 physical chassis and create the vCMP guest for LTMs.

     

    I can create two trunk uplinks(with multiple VLAN ID) and connect each of them to PROD-1 and PROD-2 Nexus switches.

    But on the VLAN interface, we need to add both trunk interface(with tagging) since both are sharing same VLAN ID.

     

    For me, only the layer-2 configuration is unclear.

     

    Since the Layer-2 is handled at HOST level, if you use same VLAN ID, how it differentiate the traffic between Guests? since the uplinks are connected to two different switches any L2 loop will happen?

     

    Regards,

    Kannan.