Rationale for BGPDNS
For all services that are either stateless, have only short-lived or restartable sessions BGPDNS is well suited and provides equal results as true AS-based multi-homing
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- applies to HTTP, HTTPS, SMTP, POP, IMAP, FTP (in part), NNTP (client sessions)...
By keeping IP address space aggregation intact and the positive effects on AS numbers and router memory by far outweigh the negative effects of BGPDNS by requiring one IP address per server and upstream ISP