Confirmed now - the routes
ARE in the routing table correctly, yet, a traceroute follows the
wrong path...
Border 02 router, which peers with the ASN via public peering:
> /ip route print detail where dst-address=a.b.71.0/24
Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, B - blackhole, U - unreachable, P - prohibit
0 ADb ;;; AS34307 - NL-IX Route Server
dst-address=a.b.71.0/24 gateway=c.d.116.103 gateway-status=c.d.116.103 reachable via VLAN7 - NL-IX Peering distance=20 scope=40 target-scope=10
bgp-as-path="34305" bgp-local-pref=3080 bgp-med=0 bgp-origin=igp bgp-communities=65000:3080 received-from=AS34307v4 - NL-IX Route Server 01 (NL-IX)
1 Db ;;; AS34307 - NL-IX Route Server
dst-address=a.b.71.0/24 gateway=c.d.116.103 gateway-status=c.d.116.103 reachable via VLAN7 - NL-IX Peering distance=20 scope=40 target-scope=10
bgp-as-path="34305" bgp-local-pref=3080 bgp-med=0 bgp-origin=igp bgp-communities=65000:3080 received-from=AS34307v4 - NL-IX Route Server 02 (NL-IX)
2 Db ;;; AS34307 - AMS-IX Route Server
dst-address=a.b.71.0/24 gateway=80.249.209.174 gateway-status=80.249.209.174 reachable via VLAN1587 - AMS-IX Peering distance=20 scope=40 target-scope=10
bgp-as-path="34305" bgp-local-pref=3070 bgp-med=0 bgp-origin=igp bgp-communities=65000:3070 received-from=AS6777v4 - AMS-IX Route Server 01 (AMS-IX)
3 Db ;;; AS34307 - AMS-IX Route Server
dst-address=a.b.71.0/24 gateway=80.249.209.174 gateway-status=80.249.209.174 reachable via VLAN1587 - AMS-IX Peering distance=20 scope=40 target-scope=10
bgp-as-path="34305" bgp-local-pref=3070 bgp-med=0 bgp-origin=igp bgp-communities=65000:3070 received-from=AS6777v4 - AMS-IX Route Server 02 (AMS-IX)
> /routing bgp advertisements print "AS2bbbb9v4 - iBGP, BR01" detail where prefix=a.b.71.0/24
peer="AS2bbbb9v4 - iBGP, BR01" prefix=a.b.71.0/24 nexthop=c.d.116.103 as-path="34305" origin=igp local-pref=3080 med=0 communities=65000:3080
So, we have received the route through our peering arrangements, we have 4 paths available. Yet, we only advertise 1 path to our Border 1 router (we should advertise at least 2 paths, as the preferences & communities are different)...
On Border 01, which peers directly with Border 02 (iBGP), and has a transit link (full table):
/ip route print detail where dst-address=a.b.71.0/24
Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, B - blackhole, U - unreachable, P - prohibit
0 ADb dst-address=a.b.71.0/24 gateway=c.d.116.103 gateway-status=c.d.116.103 recursive via e.f.48.35 VLAN100 - Edge Network distance=200 scope=40 target-scope=30
bgp-as-path="34305" bgp-local-pref=3080 bgp-med=0 bgp-origin=igp bgp-communities=65000:3080 received-from=AS2bbbb9v4 - iBGP, BR02
1 Db ;;; AS49544 - Transit
dst-address=a.b.71.0/24 gateway=31.204.159.165 gateway-status=31.204.159.165 reachable via sfp-plus2 - Cable S03.R13.02 & 2622 distance=20 scope=40 target-scope=10
bgp-as-path="49544,34305" bgp-origin=igp bgp-communities=65000:3000 received-from=AS49544v4 - Transit
The ACTIVE route, is supposedly going via Border 02. A traceroute however:
traceroute to a.b.71.34 (a.b.71.34), 30 hops max, 60 byte packets
1 e.f.48.129 0.455 ms 0.646 ms 0.672 ms <- CORE router
2 e.f.48.34 0.223 ms 0.262 ms 0.310 ms <- BORDER 01 router
3 g.h.159.165 <- TRANSIT
....
Traffic is not being send Border 01, Border 02, Peering. It is instead going Border 01, TRANSIT. Which is NOT what the routing table on Border 01 indicates.
Refresh/Resend the peering sessions, and the problem resolves itself after the BGP tables are loaded a second time. Happens with IPv4 as well as IPv6 traffic.
EDIT: From the ROUTER ITSELF (i.e. Border 01 router) the traceroute is correct (i.e. Border 01 -> Border 02 -> Peering). From devices BEHIND Border 01, the traceroute is incorrect (Border 01 -> Transit).
Route Cache is disabled, and RP Filter = no (on both routers)