SQL 2012 :: Query To Filter Out Specific Data?

I need to return 1 ip address for each machine. I can easily achieve this with using group by and return max(ipaddress) however I would like to filter out specific range '192.168.%' but only want to do that if machine has more then 1 ip address. If the machine has only 1 ip address then it can return it even if its '192.168.%'

below is test table to show sample data

CREATE TABLE dbo.[testip](
[machineid] INT NULL,
[ipaddress] [varchar](20) NULL
)
GO
INSERT INTO [dbo].[testip] ([machineid],[ipaddress]) VALUES (1,'155.119.1.22')
INSERT INTO [dbo].[testip] ([machineid],[ipaddress]) VALUES (1,'192.168.1.5')

[code]....