Why would you want to have 2 sets with different IP?
It will only pick up the first entry.
But if you are talking about redirecting users if SERVER1 is down to SERVER2, then you can have additional query lines along with timeout value.
I dont remember the exact syntax but hope you get the picture.
MYSERVER 3 5
master tcp blah ip1
query tcp blah ip1
query tcp blah ip2
But this is only for the clients.
Oh if you have 2 n/w listeners
# PRODUCTION server with two network listeners
PRODUCTION<tab>3<tab>3<newline>
<tab>master tcp ether SERV_CORPNET 4559
<tab>master tcp ether SERV_ENGNET 5479
<tab>query tcp ether SERV_CORPNET 4559
<tab>query tcp ether SERV_ENGNET 5479