BGP
4 posts tagged BGP.
The Site-to-Site VPN tunnel that waits to be called
By default, AWS never initiates a Site-to-Site VPN tunnel. Your device has to. So a tunnel that only carries traffic AWS originates — monitoring, a scheduled job, a backup pull — comes up, idles, drops, and stays down until something on your side sends a packet. The fix is one setting that most people have never seen, and it requires IKEv2.
Networking6 minDirect Connect has a button that breaks it on purpose, and almost nobody presses it
StartBgpFailoverTest takes a virtual interface's BGP session down for a duration you choose, so you can watch traffic move to the backup path before an outage does it for you. It is the only honest way to know a hybrid failover works, it has a three-hour default most people do not expect, and it can be stopped at any time.
Networking6 minBFD negotiates to the slower peer, so your failover is as fast as their config
You can set a 300 millisecond interval on your side and still get whatever the other end asked for. Intervals negotiate to the slower value and can be asymmetric, which means detection time is not a number you control alone.
Networking5 minA stale static route silently shadows the BGP route you are advertising
VPC route priority puts static routes above propagated ones at the same prefix. So a leftover static route wins over a healthy BGP advertisement, and the routing table looks correct because the route is there.
Networking5 min