How to calculate the MS NLB multicast mac address from a unicast IP address

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If using Microsoft Network Load Balancing (NLB) set-up in multicast mode you can calculate the multicast mac address from the unicast NLP cluster IP address as follows:

Convert each octet of the unicast IP to Hexadecimal, the multicast mac is 03-bf-WW-XX-YY-ZZ. e.g. IP 199.99.20.70 Convert to Hex:

Decimal Hex
199 c7
99 63
20 14
70 46

The multicast mac address would then be:

03-bf-c7-63-14-46