f5 link controller iroule help

hi all !

 

i have a link controller with 2 routers ( 2 ISPs) connected to it

 

 

i need help creating an iroule that check if this is the source ip is 84.6.6.90 with port 443 and the line to isp A is ok so the link controller will pass the traffic with no NAT , BUT this is our issue , when the line to ISP A is dead he should do a static NAT to this traffic to 212.2.2.100 and pass the traffic to ISP B ..

 

 

can you help me pls ?