arp querier/responder for multiple ip addrs on multiple networks using the same interface

[Eddie Kohler]

> We want to emulate a system of multiple networks that are all slower than
> Ethernet.  The idea is that we build simulated network & inter-network link
> emulators using classifiers for inter-simulated-net routing.  When a packet
> is rec'd from the real network interface, a click Classifier selects by src
> addr the appropriate simulated network emulator chain that imposes latency &
> bw restrictions.   Whenever a packet leaves a simulated network chain, it is
> routed via a Classifer (by dst addr), either back to the appropriate network
> interface (via ToLinux) or to another bw/latency chain that terminates in
> another click-simulated network emulator chain.

Also, I in no way want to discourage you from using Click :), but FreeBSD's
dummynet facility, combined with virtual interfaces, may already do what
you want. If it doesn't, I'd be interested to know why not (help me to
understand your application better).

http://info.iet.unipi.it/~luigi/ip_dummynet/

     dummynet is a flexible tool originally designed for testing networking
     protocols, and since then (mis)used for bandwidth management.

     It simulates/enforces queue and bandwidth limitations, delays, packet
     losses, and multipath effects. It also implements a variant of Weighted
     Fair Queueing called WF2Q+. It can be used on user's workstations, or on
     FreeBSD machines acting as routers or bridges.

Eddie