VPP static mapping to realize DNAT

Basic interface configuration:

DBGvpp# set interface state port7 upDBGvpp# set interface state port8 upDBGvpp# set interface ip address port7 50.1.1.1/24DBGvpp# set interface ip address port8 192.168.1.203/24

Network topology:

|------------| |------------| |---------------|| 50.1.1.2 |---------| vpp |------|----| 192.168.1.103 ||------------| |------------| | |---------------|Host-A port7 port8 | Host-B|| |---------------||----| 192.168.1.114 ||---------------|Host-C(FTP-Server)

Enable NAT44 configuration:

DBGvpp# nat44 enable

The following 192.168.1.203 is the real IP address of interface port8, and execute DNAT.The configuration is the same as the above SNAT, which uses VPP static address mapping.

# nat44 add address 192.168.1.203# set interface nat44 in port7 out port8# nat44 add static mapping local 50.1.1.2 external 192.168.1.203## show nat44 static mappingsNAT44 static mappings:local 50.1.1.2 external 192.168.1.203 vrf 0## show nat44 interfacesNAT44 interfaces:port8 out## show nat44 addressesNAT44 pool addresses:192.168.1.203tenant VRF independent

Execute 192.168.1.103 -> ping -> 192.168.1.203:

1. Capture the packet on the host 50.1.1.2, you can see the packet: 192.168.1.103->50.1.1.2, and the replacement of the destination address is performed.
   2) Capture the packet on the host 192.168.1.103, and see the packet: 192.168.1.203->192.168.1.103, where the source address is replaced.

The following NAT session looks like:

# show nat44 sessionsNAT44 ED sessions:-------- thread 0 vpp_main: 2 sessions --------i2o 50.1.1.2 proto ICMP port 41039 fib 0o2i 192.168.1.203 proto ICMP port 41039 fib 0external host 192.168.1.103:0i2o flow: match: saddr 50.1.1.2 sport 41039 daddr 192.168.1.103 dport 41039 proto ICMP fib_idx 0 rewrite: saddr 192.168.1.203 icmp-id 41039o2i flow: match: saddr 192.168.1.103 sport 41039 daddr 192.168.1.203 dport 41039 proto ICMP fib_idx 0 rewrite: daddr 50.1.1.2 icmp-id 41039 txfib 0index 0last heard 254.15total pkts 5, total bytes 420static translation