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Summary:
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1. Configure a static, default route on R1 pointing to the ISP.
2. Configure a static default route on R2 pointing to R1
3. Configure a static default route on R3 pointing to R2.
4. Option: using RIP for R2 and R3 rather than the static default routes.
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1. Configure a static, default route on R1 pointing to the ISP.
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R1.
ip route 0.0.0.0 0.0.0.0 192.168.1.100
#Test: add a couple of loopback IPs on ISP so we can test
int l0
ip address 4.2.2.2 255.255.255.255
int l1
ip address 8.8.8.8 255.255.255.255
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2. Configure a static default route on R2 pointing to R1
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R2.
ip route 0.0.0.0 0.0.0.0 10.24.0.1
#Test: you can't ping 4.2.2.2 at this point because ISP doesn't have a route back to R2 since ISP doesn't know anything about 10.24.0.0/24 network. However, you can test ping to R1's serial port because R1 does know how to get back to R2.
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3. Configure a static default route on R3 pointing to R2.
R3.
ip route 0.0.0.0 0.0.0.0 10.15.1.13
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#Test: ping to R1's serial/WAN port
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4. Option: using RIP for R2 and R3 rather than the static default routes.
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R2.
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no ip route 0.0.0.0 0.0.0.0 10.24.0.1
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R3.
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no ip route 0.0.0.0 0.0.0.0 10.15.1.13
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R1.
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router rip
default-information originate
#Test:
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-Yu
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