|Originally posted by delusion602
So we have a Buffalo unit at IP address "A", taking packets from a downlinked ReplayTV at IP address "B", and passing them along to uplink router at IP "C".
Do you still maintain that the Buffalo is acting as a dedicated bridge, and is not doing any IP layer routing? If so, you may want to refrain from taking the CCIE exam just yet.
You have a condescending attitude which is somewhat problematic but
they do not test for that in exams.
To prove to yourself that there is *no* IP layer3 routing in the configuration
I described (and which most of us are using) there is a simple test you can
do (everything is connected to the LAN ports of the Buffalo, WAN ports are
traceroute from Laptop1 to Laptop2. There will only be *1* line in the
traceroute. There can be *no* IP layer3 routing because Buffalo1 and
Buffalo2 have no clue how to get to 10.0.0.0/8 network. Further if there
was routing, there would be more than 1 line in the traceroute.
Just because Buffalo1 and Buffalo2 have IP addresses does not mean
they process the packets at IP layer3. Visually you just have the wrong
picture of how things are architected.
You should view the Buffalos as separate components internally connected
rather than one monolithic device.
So from a *logical* rather than physical perspective the Buffalo is actually:
4-port switch with WDS wireless uplink
wired ethernet (internal to device)
Buffalo router device
The Buffalo is essentially just another device hanging off the switch and
when you create a WDS wireless uplink, the Buffalo router device sub
module is not involved with the WDS uplink.
The device as a whole (in particular the switch and WDS uplink sub
modules) however is involved at layer2 with the MAC address tables
just like any switch would be. All direction of traffic across the WDS
wireless link are done using MAC address only.
There is a 4-tuple of MAC addresses in the wireless frame header
1) initial source
2) final destination
3) intermediate sender
4) intermediate receiver
WDS is a layer2 bridging technology and all the directing of packets is
based on MAC addresses described above. This is regardless of what
IP address you have the Buffalo LAN configured to.