multi-homing fixes

Randy Bush randy at psg.com
Sat Aug 25 00:22:03 UTC 2001


> If you were in a position where you did NOT have your own previously
> allocated swamp/b/a space, you wanted to multihome to a few different
> providers in such a way that you were globally reachable no matter who
> went offline and you only needed a /24 or less, what would you do?

haven't thought about it for a while, but ...  probably rethink my
requirements a bit.  

my small experiences running a site or two lead me to think physical
diversity in the local loop is by far my biggest concern, like ten to
one or worse over a provider problem.

and then, almost all the provider problems i can remember my site
having were a router needing geritol or, quite rarely, a pop going
bad.  i have not had a whole isp go out from under me since the bad
old days.  but i have tried to stay with reliable providers.

so i might seriously consider dual homing to separate pops of a
single very reliable isp, and concentrating my energy on physical
diversity of the local loop.

if i really felt the need for multiple providers, i might do a double
nat, but with full 1:1 mapping, i.e. pure address aliasing, not space
compression.  of course, some persistent connections would be lost in
the case of a link failure.  but insurance against very rare cases is
ok if the expense is incurred on the rare case.

randy



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