[RndTbl] wireless basics

Dan Martin ummar143 at shaw.ca
Sat Jan 21 16:19:56 CST 2012


I want to do some (hopefully minor) tinkering with my wireless network, but it is clear that I don't get some basic concepts.  To help me visualize my network at the NIC / MAC address level, could someone explain who has MAC addresses and why?

I have a network connected (indirectly) to a cable modem.  A linux box serves as a gateway.  It is connected by ethernet to the WAN port of an airport extreme base station.  2 windows machines are connected to LAN ports on the base station.  1 windows machine and 2 Macs are connected by wireless.  All the machines have manually assigned IP addresses, and the base station is configured in "bridge mode" since it appears the other options involve NAT or DHCP.

My gateway box is acting as a router.  It has 2 NICs (hence 2 MAC addresses), 1 for inet connection and 1 to the LAN.

When I used a CentreCom router, on the other hand, it appeared invisible, or at least I wasn't aware of any MAC addresses for the router.

The utility for the base station lists what appears to be 2 MAC addresses: an "AirPort ID" and an "Ethernet ID".  I have assigned the base station an IP address.

The Mac computer I'm using, attached by wireless, does not show the base station in the routing tables [except the "Ethernet ID" does show in the IPv6 tables].  traceroute shows only a single hop to the gateway.

Am I to assume that dedicated routers - unlike my Linux gateway - appear invisible in the network and just magically connect nodes to each other?  If so, what are the MAC addresses on the base station for?  Just to access the box itself for configuration?  To access something connected to its USB port?


Dan Martin
GP Hospital Practitioner
Computer Scientist
ummar143 at shaw.ca
(204) 831-1746
answering machine always on




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