I propose that MICE enable BGP ADD-PATH capability (RFC 7911) on the route servers (in TX mode only). This is negotiated BGP capability, so we do not need any per-participant setting for it. ADD-PATH is useful if the best path route is being filtered but another route would not be. We discussed adding this at a UG meeting years ago. There are other IXPs that have this enabled. For example, this one: https://www.bcix.de/ixp/content/0/route-servers In terms of timeline, I propose something like this: * January 9: Enable it on Route Server 1. * January 16: Enable it on Route Server 2. The actual change looks like this for the RS1-only piece, and then the conditional would be removed when we want to deploy to RS2: --- a/roles/ixpmanager/files/mice/api/v4/router/server/bird2/neighbors.foil.php +++ b/roles/ixpmanager/files/mice/api/v4/router/server/bird2/neighbors.foil.php @@ -315,6 +315,9 @@ protocol bgp pb_<?= $int['fvliid'] ?>_as<?= $int['autsys'] ?> from tb_rsclient { import filter f_import_as<?= $int['autsys'] ?>; table t_<?= $int['fvliid'] ?>_as<?= $int['autsys'] ?>; export filter f_export_as<?= $int['autsys'] ?>; +<?php if( $t->router->router_id == "206.108.255.1" ): ?> + add paths tx; +<?php endif; ?> }; <?php if( $int['bgpmd5secret'] && !$t->router->skip_md5 ): ?> password "<?= $int['bgpmd5secret'] ?>"; -- Richard