18 Sep
1997
18 Sep
'97
5:36 p.m.
This isn't quite correct (though it's peripheral to your main argument). An EBGP speaker is free to advertise routes containing 9999 to 9999. Furthermore, 9999 is free to accept routes containing 9999. Whether 9999 chooses to do this or not is, as the saying goes, "purely a local matter." Likewise whether 9999's peers choose to refrain from sending such routes.
Some BGP implementations, gated for one, may be configured to accept routes with the router's own AS number in the path. Loop suppression is still provided by limiting the number of times it may appear. (Hi, Dennis.)
This is actually useful in some circumstances.
serious question: what circumstances? /jws