F5 Can not change Ip NAT to IP other when line downs

Hi all

 

 

I'm a new F5 , My F5 is GW internet for users to internet and publish some server to internet.

 

 

Current , I'm facing problem as:

 

 

Users---------F5--------3 lines internet

 

 

I have config virtual servers

 

 

Destination : 0.0.0.0/0.0.0.0

 

Services port: All

 

Type:Performance layer 4

 

Protocol: ALL

 

VLAN and Tunnel Traffic :all

 

SNAT Pool :AutoMap

 

Default Pool:Default_GW_Pool

 

Default Persistence Profile:Dest_Addr

 

 

Anything work good , but when 1 lines goes down then some users can not access to internet ,

 

 

I used tcpdump then i saw this is user of address translation to ip public of line Internet1 , so when the line internet1 went down then the user can not access internet ( the Users other work good) . ( Default gateway pool is Round robin loadbalance )

 

 

 

Why does the line internet goes down then F5 can not NAT source of users to Ip public of line internet other ?

 

Can you pls give me a solution to the fix it ?

 

 

Many thanks all !