the netgroup on the DM does not support specifying IP address .
from the 7.1 Configuring VNX™ Naming Services
Create or edit a netgroup file
Each line of the netgroup file defines a group and has the format:
groupname member1 member2 ...
Each member is either the name of another group or indicates specific hosts, users,
and domains, referred to as a triple, as follows:
Any of the triple’s three fields can be blank, meaning all the values in that field are
included. A dash in any of the fields means there are no valid values. For
example, the following line defines a group called ouruniverse that consists of all
hosts and users in the NIS domain ourdomain.
The following lines define a group called ourhosts that includes all of the hosts but
none of the users in the domain, and a group called ourusers that includes all users
but no hosts.
The following line defines a group called ouruniverse that consists of two hosts
hostatlanta and hostboston.
Note: IP addresses are not allowed.
A netgroup file can include as many lines as required; however, each line must be
less than 1 KB in length. If necessary, a line can be continued on another line by
using the backslash (\) as a continuation character. A triple, however, cannot be
split across two lines.
Note: If you use a backslash (\) as a continuation character, it must be the last character on
the line. It cannot be followed by spaces.