Hi, I have some questions about port forwarding on Cisco router and *nix ip tables dnat
Am I right in my guess?
When I have a Router with LAN interface 10.1.1.1/32 ip address and WAN Dialer interface with 5.5.5.5/32 ip address and I make port fowarding from WAN to LAN like this:
ip nat inside source static tcp 10.1.1.2 80 5.5.5.5 8080
that means packet which come to my WAN interface will be open by my Router, and it will change destination field from 5.5.5.5:8080 to 10.1.1.2:80, and then forward to LAN 10.1.1.2:80
same operation for *nix router when doing DNAT
IPTABLES -t nat -A PREROUTING -p TCP -d 5.5.5.5 --dport 8080 -j DNAT --to-destination 10.1.1.2:80
means packet which come to my WAN interface will be open by my *nix router, and it will change destination field from 5.5.5.5:8080 to 10.1.1.2:80, and then forward to LAN 10.1.1.2:80
Am I right that is same operations *nix call it DNAT cisco call it port forwarding? or cisco use other mechanism when port forwarding occurs, and it does not change packet header int destination field?
thanks