Route Server Filters at IXPs and 4-byte ASNs

[Aris Lambrianidis <effulgence () gmail com>]

Food for thought:

- ASNs can be reused at different locations by IXPs, barring perhaps
certain business or administrative reasons. Ask Equinix.

- For IXPs that already have 16-bit ASNs for route servers, this saves additional 
allocations from RIRs and mitigates concerns for the IXP getting potentially a 32-bit ASN, 
thus having trouble with BGP communities as described. Having a single ASN
may raise other issues but it is an option. 

- I believe it would help if RIRs reserved 16-bit ASNs
in addition to IPv4 micro allocations for IXPs, until a formal
solution can be finally found about the 32-bit ASN BGP communities issue. 

Aris Lambrianidis