I have a customer who has done this and it worked:  In the "link" lines in llttab you put the IP address of server and in the "set-addr", the NAT IP address - example:

set-node /etc/VRTSvcs/conf/sysname

set-cluster 1

link hb-normal /dev/udp - udp 50100 - 10.5.0.1 -

link hb1-nat /dev/udp - udp 50101 - 10.5.1.1 -

 

set-addr 1  hb-normal 10.6.0.1

set-addr 1  hb-nat 173.194.34.98

 

#disable LLT broadcasts

set-bcasthb 0

set-arp 0