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where destination is unknown, By default the router will forward all traffic to ISP.
A default route is the route that takes effect when no other route is available for an IP destination address.

APPLE
enable
conf t
hostname Apple
int fa0/0
ip add 192.168.1.1 255.255.255.0
no shutdown
int fa0/1
ip add 200.1.1.1 255.255.255.0
no shutdown
ip route 0.0.0.0 0.0.0.0 200.1.1.2
ISP
enable
conf t
hostname ISP
int fa0/0
ip add 9.1.1.1 255.0.0.0
no sh
int fa0/1
ip add 200.1.1.2 255.255.255.0
no sh
ip route 192.168.1.0 255.255.255.0 200.1.1.1
This static route we will not use in real world as already we have NAT on our routers. NAT convert private ip into public IP.
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