Hello everyone!
Today I want to share with you an experiment on NAPT.
I have built a simple topology. There are two network segments (192.168.0.0 and 192.168.1.0) in the enterprise intranet. Now intranet 1 and intranet 2 need to access the Internet.
The ISP assigns three public IP addresses: 12.x.x.1, 12.x.x.2, and 12.x.x.3 to the enterprise. 12.x.x.1 is used by GE 0/0/1 of AR1, and 12.x.x.2 and 12.x.x.3 are used by intranet computers for NAPT.
Before configuring NAPT, let's perform a ping test.
PC3 to ping PC4:
PC6 to ping PC4:
PCs on enterprise intranet 1 and enterprise intranet 2 cannot access the Internet.
To configure NATP on the edge router AR1, perform the following steps:
Create a public address pool.
Need to define the private network segment that is allowed to access the Internet through NAPT through ACL.
Configure NAPT on GE 0 / 0/1 of AR1 connected to the Internet.
After configuring NATP, we use PC3 to ping PC4.
WHY IS THE ENTERPRISE INTRANET STILL UNABLE TO ACCESS THE INTERNET?
Queried the route and found that AR1 does not have a route to access the Internet.
Run the ip route-static command to add a static route.
AR1:
AR2:
Now, we perform the ping test again.
PC3 to ping PC4:
PC6 to ping PC4:
As shown in the preceding figure, intranet 1 of the enterprise can access the Internet, but intranet 2 of the enterprise still cannot access the Internet.
Queried the route of AR3 in the enterprise. It is found that AR3 does not have a route to access the Internet.
Based on the topology, add a default route on AR3 and AR1.
R3:
R1:
Perform a ping test.
PC6 to ping PC4:
Both enterprise intranet 1 and enterprise intranet 2 can access the Internet.
Now let's verify that the Internet cannot directly access the intranet.
PC4 to ping PC6:
For more information, please click NAT.
Thank you so much for reading and I hope it will help you!
