You cannot have the exact same subnet on both interfaces. You could have two that overlap and the most-specific one would take precedence. I don't see any reason for setting the firewall up like that, though.
I check both have same subnet /29.
If you mean "Can you have two interfaces with the same subnet mask?" then the answer is Yes, of course. If you question is "Can you configure two interfaces with the same IP address and the same subnet mask?" then the answer is No.
Seems in this environment it is working fine with same subnet mask /29 strange.
Under what circumstance we can have two interfaces with subnet ?
I'm not sure you understand what Sam is saying. Each interface can have the same subnet mask value (/29, /24, etc...), but the interfaces themselves cannot be configured with the same address range.
Interface 1 - 220.127.116.11/24 & Interface 2 - 18.104.22.168/24 (both /24, but different address ranges) = OK
Interface 1 - 22.214.171.124/24 & Interface 2 - 126.96.36.199/24 (both part of the same address subnet) = Not OK.
I got it now Phil