Understanding uRPF Loose Mode /Strict Mode,
Let's say we have R1 connected on both of its 2 interfaces to R2 and R3
R1 interface IP address(192.168.12.1/24) connecting to R2
R1 interface IP address(192.168.13.1/24) connecting to R3
R2 interface IP address(192.168.12.2/24) connecting to R1
R3 interface IP address(192.168.13.3/24) connecting to R1
R2 has a loopback 0 with ip address 22.214.171.124/32
R1 has static route : Ip route 126.96.36.199 255.255.255.255 192.168.12.2
For test purpose I have created lopback 0 on R3 with the same IP address 188.8.131.52/32 as the loopback 0 on R2
With Strict Mode or Loose Mode configured, I can ping from R2 (source Loopback 0:184.108.40.206) to R1 (192.168.12.1)
I can see the ping replies. but I cannot ping from R3 (Source Loopback 0: 220.127.116.11) to R1 (18.104.22.168).
However when reading online, it states that with Loose Mode, R1 will accept packets from R3 and with Strict Mode it does not.
from my side, I still cannot see the difference between Strict/Loose Mode as both will cause Ping fails from R3 source loopback 0 to R1
Any clarification on this ?