[c-nsp] OSPF to ISIS migartion

[joshua sahala]

On Wed, Sep 23, 2009 at 1:50 AM, jack daniels <jckdaniels12 at gmail.com> wrote:
[cut]
> WHAT CONSIDERATIONS TO KEEP IN MIND BEFORE MIGRATION.


as others have shared, vijay's presentation and methodology were spot on:
   - have ALL of your configurations pre-written/staged/tested
   - have a well organised plan of what order you will touch
everything that is being converted,
       or clear boundaries if you have to do it in stages so that
nothing is missed
   - execute the plan
   - verify the config on every device that was supposed to be touched

i've gone through the dance two times now (and preparing for a third
^_^ ) and haven't had any issues beyond lack of vendor support (cisco)
for the protocol.

wrt to the poster who said "just run ospfv3", i would disagree:  you
are adding significant complexity by running yet another routing
protocol (yarp?!?!) across the infrastructure, as well as adding
operational overhead.  in one of the two cases i've converted, it was
largely because we didn't want to run two distinct igps, and is-is is
a single and arguably simpler protocol  (<insert rant about the
simplicity of tlv versus lsa and size of code-base>)

my $0.02usd
/joshua
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