small multihomed organizations

Lee Howard lhoward at UU.NET
Mon Aug 6 15:42:59 EDT 2001

We occasionally have customers who will be multihomed with us and another
provider, and who need address space, but can't justify a /24 based on
usage and host count.  If we give them less than a /24, no traffic will 
come down their other line. [1]

ARIN's current policy, as I understand it, is that multihoming is not
justification for a /24.  I would like to hear recommendations and best
practices from others for how to address the customer (pun intended)
without violating ARIN policy.  Should ARIN accept multihoming as
justification for a /24?


Lee Howard

[1] Here's why:  Most ISPs do not accept prefixes longer than 24 bits, so 
they will ignore our propagation of our customer's /24, and they will 
ignore the route announced from the customer's other ISP.  Since we also
announce a large aggregate (say, a /13 from which that /24 was allocated)
those peers will send traffic to us, which we can then forward to our
customer.  But they'll never hear the other ISP's announcement, unless our
network was completely cleared off the map and the aggregate were withdrawn.

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