Recently, I have read about "policy switch", which handles the network policy information. I want to know the importance of that switch in the network.
Logically, all switches are connected to the controller. Physically, it depends... if you are using in-band or out-of-band management.
Marcio Minicz Thank you for the response, I want to know can we disconnect data plane from the control plane by attacking only one switch (i.e. the policy switch)?
That is the idea of out-of-band management, construct a second network using switches that only send/receive control messages, i. e., dedicated for management the devices.
Can you send a reference where you read the term "policy switch"?
Marcio Minicz You can read in this paper on page 4, they discuss an "access switch"
https://www.researchgate.net/publication/324411560_Disrupting_SDN_via_the_Data_Plane_A_Low-Rate_Flow_Table_Overflow_Attack
I haven't read it in many papers, however some of them discuss, NAT Switch, Access Switch, Policy Switch, which performs the core management of all the other switches.