After you integrate BIG-IP
DNS into a network with BIG-IP
Local Traffic Manager (LTM), or vice versa, the
BIG-IP systems can communicate with each other. If Access Policy Manager
(APM) is also installed on one of the BIG-IP systems with LTM, APM
calculates virtual server scores and provides them to BIG-IP DNS.
The calculation is based on the number of active access sessions. APM calculates two usage
scores and assigns the higher of the two to the virtual server:
- One usage score is based on the BIG-IP system licensed maximum access concurrent sessions and
the sum of the current active sessions on all the access profiles configured on the system.
- The other usage score is based on the maximum concurrent user sessions configured on the
access profile attached to the virtual server and the current active sessions count on the
A value of 0 indicates no capacity and a value of 100 means full capacity available on the
Note: The calculations do not include connectivity session usage.
Use a BIG-IP DNS global load-balancing pool for BIG-IP DNS to load balance APM users based on the virtual
server score. BIG-IP DNS uses virtual server score in the VS Score and Quality of Service load balancing
methods for global load-balancing pools.
These tasks must already be complete before you begin:
- BIG-IP DNS and APM must be installed and configured.
- Either BIG-IP DNS must be integrated with other BIG-IP systems on a network or BIG-IP LTM® must be integrated into a network with BIG-IP DNS.
- The health monitors defined for the BIG-IP DNS and LTM servers must include bigip; otherwise, APM
does not calculate virtual server scores and send them to BIG-IP DNS.