For the case of using nat in a ISP environment you want your default route pointing to the outside interface. From the ISP point of view they will only have the addresses you have in the NAT table. They know nothing about your internal network. Depending on how many addresses you have the ISP will just have routes for these addresses and they will all be sent to your router. If you have only 1 then all the traffic appears to come from the router itself.
After it gets to your router this is where the direction of nat traffic matters. When the traffic comes back the address is translated from the public ones to your private ones. Since you may have multiple interfaces on your router that are NAT inside interfaces the router does not know where to send the packet until after it converts it. This is why when traffic goes from outside to inside the translation is done before the lookup.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...