17 Sep
2019
17 Sep
'19
7:41 a.m.
On 16/Sep/19 20:26, Töma Gavrichenkov wrote:
Not always.
No, longest match ALWAYS wins.
E.g. imagine an ISP who has two connections to the outside world: one through a major ISP and the other through an IX.
Such an ISP would be quite inclined both financially and technically to import routes just from the IX and set the default to the upstream ISP link. Therefore, an advertisement from the IX would always win no matter the length.
Which is why I included, in my previous message: So, for example, if the upstream to whom you are sending the /21 doesn't do anything about how they learn the /22 from another source, (for their network)... Mark.