quote of the day... odom

wendell, you have the floor:

Neighbors—Two routers that share a common data link, that exchange Hello messages, and the Hellos must match for certain parameters.


Adjacent (fully adjacent)—Two neighbors that have completed the process of fully exchanging DD and LSU packets directly between each other.

and further (this is the big one)

if a DR is elected, the election occurs after the routers have become
neighbors, but before they send DD packets and reach the ExStart neighbor state. When an OSPF router reaches the 2-way state with the first neighbor on an interface, it has already received at least one Hello from that neighbor.

translation:

after neighbors but before adjacency:

hellos begin at init...

two-way is established upon hello reception NEIGHBORS

exstart determines master/slave

exchange (exchange dd)

loading compare dd... bring lsa's up to speed with lsr's... ACKNOWLEDGE

full = synchronization

wendell on tshoot topologies...

in hunting for the compelling reason to use frame on the 2 tshoot topologies that do not specifically include frame, the best i could come up with is this:

http://www.networkworld.com/community/node/60349

What you get here is the ability to have multiple FR PVCs between each pair of the 5 routers. Having multiple PVCs between a pair of routers allows for layer 3 redundancy between that pair. More importantly, this one physical topology can be configured to create a logical topology that put the routers into a linear sequence (much like the sample TSHOOT topology in the TSHOOT demo), or a full mesh, or anywhere in between.  

So, why FR and not pt-pt? Most of the time, the key ROUTE and TSHOOT layer 3 learning points have no dependencies on the layer 2 technology. And when layer 2 does matter, the majority of the interesting cases use FR. When you really need the routers connected over a LAN or pt-pt, re-cable and re-config as needed.

that's pretty weak and just as i thought... wendell writes "interesting" and i read "frame introduces various finicky behaviors with routing protocols that throw curve balls when you're expecting heat"...

like hyman roth said, "this is the business we've chosen..."

so why not leave ATM in as well?

nobody uses that shit anymore either...

frame should be moved out of ccnp and mpls brought back in...

ODOMETRY...

from the master himself...  yeah, yeah, he's a tough read...  he's often tangential, but there is only one WENDELL ODOM...

if you are not  keeping up with his musings at his blog, if you have not put his link in your favorites, and if  you are not using his books, abusing them, sleeping with them, shame on you...

his blog is here http://ccnaskills.wordpress.com/

he's posing an interesting STP dilemma/puzzle...

who's your daddy?  Odom's your daddy...