5. NAT overload

5.1. Configuring

For the sw3 network, we'll also configure NAT, but with NAT overload.

Once again, we'll need to define the inside and outside of the network. The outside is ofcourse dc_core again. And we'll configure e0/1 as
int e0/1
ip address
no shut

We'll define the NAT interfaces:
int e0/0
ip nat outside
int e0/1
ip nat inside

For static NAT, we defined the translations next. NAT overload uses an ACL as source:
ip access-list standard NAT

For the ACL, we used a named ACL. Also, for ACLs, wildcard masks are used not netmasks.

And lastly, configure the NAT:
ip nat inside source list NAT interface e0/0 overload

And we're able to ping host4 from host8:
vagrant ssh precise8 -c 'ping -c1'
PING ( 56(84) bytes of data.
64 bytes from icmp_req=1 ttl=254 time=25.9 ms
--- ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 25.949/25.949/25.949/0.000 ms
Connection to closed.

And the result for the NAT will be:
R3#sh ip nat translations
Pro Inside global      Inside local       Outside local      Outside global

Or, if you start an ssh from host8 to host5: