Alert Rules

Hi all,

     I want to understand the rule mechanisam. I have a network of 5 machines added in NPM.

a:  172.172.1.1

b:  172.172.1.2

c   172.172.1.3

d:  172.172.1.4

e:  172.172.1.5

Now , I want to make different groups to whome the notification will be sent. like there are 2 groups

1:  Network Administrators  (NA)

2:  Server Administrators     (SA)

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I want "Goes down" notification of server " a, b , c " wil sent to Group (NA)

while "Goes down" notification of " d,e " will sent to Group (SA)

For this kind of rule what I can create???