Issue in HA || USG 6500 and S5700

@Sandesh hi bro,
you mean you configure istack on S1 and S2, but when S1 hang up, U1 forward the traffic to S1 either. Am I right?
but when S1 hang up, the link between S1 and U1 is down, how the U1 forward traffic to S1, or is there something I missed?

Hi Chenhui,

I found when S1 goes down, then traffic will forwarded to S2 then it will stuck. I want traffic will go beyond the firewall. F1 was in active and F2 was in standby mode.
My concern is if traffic reached to S2 then it will try to send via F2 but F2 is in standby mode.
How this can be achieved?

hi @Sandesh,
from your topology and description, S1 and S2 run stack, F1 and F2 work in main/standby mode, but there is a problem, there is no link between F1 adn S2, F2 and S1,  this will lead the problem as you said. just like the figure below show,

won't the standby firewall forward traffic?

Hi Chenhui,

Actually i thought to connect according to your idea as well, but the issue could be the gateway for U1. If firewall and switchs connected crossly i.e F1 to S2 and F2 to S1, then if s1 goes down s2 will forward the traffic to F1 connected interface. In that case, doesn't we have to change the gateway IP of U1? How to achieve this task? I think VRRP is also not possible in this case.