Vocus used to (and probably still do) have a script to prevent transit theft/leakage that will also block more specific prefixes advertised by downstream customers from other peering and transit. If you are advertising the /23 to them and pre-pending it, it's likely still going to block /23 or longer from other networks. If they don't, then hey, free transit...
They do have a looking glass at https://lg.vocus.network/ that you should be able to use so you can observe what's happening to your prefix on their network during a failure and work out why you are seeing long fail-over times. Macca On Tue, May 2, 2023 at 9:01 AM Lincoln Dale <[email protected]> wrote: > All of what MMC said. :) > I'd also add: check the prefixes you're announcing via various looking > glasses - Vocus and TPG both have ones, but you can go wider too and see > what others view you as too. Some nice visualizations from tools like > bgp.he.net where you can see their upstreams and how connectivity might > work. > > Remember that in routing, the longest prefix always wins, and BGP path > selection doesn't even come into that. > Make sure that your upstreams are accepting your announcements. You cannot > announce a more-specific than a /24 and have the world accept it, but it > might be that the two /24s you're announcing aren't accepted either, > depending on what IRR policies are. You can at least verify that. > (I'd have done that but don't know your prefixes or ASNs as you didn't > post them.) > > BGP route propagation does not take 10-15 minutes for an update or > withdraw to happen. It's way way quicker than that. > > > cheers, > > lincoln. > > > On Tue, May 2, 2023 at 8:51 AM Matthew Moyle-Croft <[email protected]> wrote: > >> Have to remember some BGP basics: >> >> 1) longest prefix (eg. /24 in your case) will always win. >> 2) localpref will always win when comparing identical prefixes. >> 3) A network will always use localpref to prefer directly connected >> customer routes. >> 4) ASPath length is not going to overcome the above. >> >> What does "failover" mean to you? When there's a failure, look at what >> Vocus and TPG have in their route tables and the timing. Also check, are >> you actually withdrawing the routes during failure? >> >> MMC >> >> On Mon, 1 May 2023 at 18:09, Steven Waite <[email protected]> wrote: >> >>> Good evening >>> >>> I hope everyone is well. We have a /23 block broken up between TPG /24 >>> and Vocus /24 with the /23 advertise to both Vocus and TPG for failover. >>> This worked will until recently as we noticed increasing failover times >>> during maintenance and now takes around 10-15 minutes. Today I decided to >>> try AS path prepending away from smallest prefix wins type of approach. I >>> think Vocus and TPG ignores prepending as these are local routes thus the >>> local route is preferred even with a lot of prepends. I would love to >>> achieve the same thing via communities if it’s possible. Is someone able to >>> share communities numbers that I should be using for Vocus/TPG please to >>> advertise the primary route for a prefix? >>> >>> Many thanks Steve >>> >> _______________________________________________ > AusNOG mailing list > [email protected] > https://lists.ausnog.net/mailman/listinfo/ausnog >
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