A multiport switching device includes an Internal Rules Checker (IRC) that
determines forwarding information for packets received at the device. The
IRC uses an internal address lookup table to determine the forwarding
information when the received packet conforms to version four of the
Internet Protocol (IPv4). When the received packet has a longer
destination address, consistent with version six of the Internet Protocol
(IPv6), the IRC uses an externally located CPU to assist the IRC in
determining the forwarding information.
