One of the reason why UPnP (Universal Plug and Play) is enabled in our devices is because ONVIF uses this to scan the ONVIF device in the network. If you don’t need to scan ONVIF devices in the network using ONVIF method, you can switch of the SSDP Discovery Service.
SSDP protocol can discover Plug & Play devices, with uPnP (Universal Plug and Play).
SSDP uses unicast and multicast address (188.8.131.52).
SSDP is HTTP like protocol and work with NOTIFY and M-SEARCH methods.
"184.108.40.206 " is Bosch Multicast discovery address. When you block this address you cannot scan devices via multicast