Is this meant to be used within the BigFix interfaces, or for use in external systems?
Here's some sample relevance that should return the specified network attributes:
((friendly name of it) & "|" & (address of it as string | "n/a") & "|" & (subnet address of it as string | "n/a") & "|" & (gateway of it as string | "n/a") & "|" & (dhcp enabled of it as string) & "|" & (concatenation "," of (addresses of dns servers of it as string) | "n/a") & "|" & (mac address of it | "n/a")) of adapters of network