[rbridge] Ingress Rbridge address and BCN - 3rd Issue
Eric.Gray at marconi.com
Fri Oct 27 11:52:27 PDT 2006
-- [SNIP] --
--> > 3rd Issue - why use tunneling if RBridges typically may be required
--> > to retain all MAC reachability information?
--> > ==========================================
--> > There are several reasons to do this, independent of any desire to
--> > reduce memory requirements of RBridges.
--> > One is that 802.1X bridges on intermediate links are shielded from
--> > exposure to MAC addresses on separate bridged LAN segements.
--> I thought that was accomplished by adding the additional MAC header
--> between the two RBridges carrying their MACs. The 802.1X bridges
--> connecting them will only learn these two RBridges MACs regardless of
--> whether there is a destination RBridge in the shim.
Look, again, at the definition of the "3rd Issue" above.
>From you comment, it seems you missed that...
--> > Another is that the forwarding entries in RBridges are based on use
--> > of RBridge MAC addresses - which reduces the number of entries that
--> > will typically be used for forwarding by an intermediate RBridge.
--> I'm missing the destinction between what you call the "memory
--> RBridges", and "the number of entries that will typeically be used for
--> forwarding". I was assuming these were the same thing.
They are separable in a number of different ways. Trying to state it
at a high level, it is certainly possible to optimize your look-up
algorithms for a subset of frequently used entries. Caching comes to
mind, for example.
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