TOPIC:

1. On Computer 1, IP Address 192.168.1.31.
I can ping R1 vlan1 (192.168.1.30) and its router (R1) 172.31.155.226,
but I cannot ping the R2 modem (172.31.109.41) and R2 router(172.31.109.42)
and also R3 modem (172.31.104.253) and R3 router (172.31.104.254).

2. I can ping R1, R2 and R3 using these configuration

**********************
R1

interface GigabitEthernet0
ip address 172.31.155.226 255.255.255.252

interface Vlan1
ip address 192.168.1.30 255.255.255.0

ip route 0.0.0.0 0.0.0.0 172.31.155.225

*********************

R2 (I did not configure vlan1 yet because I need to find R1 and R2 configuration needed for Computer 1 not able to ping R2 router)

interface GigabitEthernet0
ip address 172.31.109.42 255.255.255.252

ip route 0.0.0.0 0.0.0.0 172.31.109.41

**********************

R3 (No vlan1 configure same reason in R2). What configuration needed for R1 and R3.

interface GigabitEthernet0
ip address 172.31.104.254 255.255.255.252

ip route 0.0.0.0 0.0.0.0 172.31.104.253

**********************
Attach file is added information on show ip route of all routers.

You would notice on these configuration that R1, R2 and R3.

R1
B 192.168.1.0/24 [20/0] via 172.31.155.226, 01:22:55

R2
B 192.168.1.0/24 [20/0] via 172.31.109.42, 06:22:55

R3
B 192.168.1.0/24 [20/0] via 172.31.104.253, 00:07:49

Hope anyone have any solutions. Please help.

Thank you.