The core translates before the IP thread, as Java's NAT threads sit
between card and Ethernet: out, the WAN address and the entry's port (ICMP
keeps its identifier); in, by remote end, port and protocol, else by the
port forwarding, which then makes a dynamic entry; a ping at the WAN
address is answered by the router, packets from outside for the LAN are
dropped, both sides pass the router's firewall, TTL 1 going out gets time
exceeded. Dynamic entries expire at Java's check each second, 300 s times
the delay factor old (55 minutes at 90 %), refreshed only by what comes in.
The home router forwards as a router does.
Measured and not taken: when a LAN endpoint sends to a second remote end,
Java gives it the entry's WAN port but no entry, and the answer stays at
the router; the core adds an entry for each new remote end on that port.
The oracle now records every card of a node (the second card of routers
was missing); the ARP and RIP runs are recorded anew and still match.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ScenarioNetwork builds home routers (their first card the WAN port) and
their port forwarding (portForwarding, through GatewayFirmware.setStaticNAT).
NatRun plays six stories on nat-home's network and writes the frames, the
calls and the router's NAT table: a ping, a UDP exchange, the same socket
to a second server (whose answer never reaches the LAN: Java keeps one
entry per LAN endpoint, for the first remote only), a TCP connection out,
a forwarded one in, and pings at the WAN address and past it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
julian.kiedaischandClaude Opus 5.5