In RouterOS v7 it seems that when two or more peers have a BGP session to the same local IP, and one of them closes, they all are closed. The log says "Idle" for those sessions.
Usually they are quickly re-established by the peer and remain up from that time.
In my config this occurs for a number of peers connected via L2TP/IPsec. I have a loopback device with a /24 RFC1918 subnet on it, and the router has one address in it. All the L2TP/IPsec clients connect to the router, get their IP (via a fixed "remote address" in the PPP secrets list), and BGP is (statically) configured between those remote addresses and the local router address. I know it can be done more automatically in v7, but part of the clients are still v6.
Those peers are often over LTE, so regularly they go down/up because the provider has disconnected them after a while and issued a new public IP on re-connection. What I see is that those BGP sessions with the same local address go down at that moment. But other BGP sessions, that are over GRE tunnels and thus have a different local IP on the central router, remain up.
Does anyone else see this? Is this "normal" for v7 or should I search for something in the config that indirectly triggers this?
It doesn't happen with the same config on v6.
Should it be considered a bug? Or is this something that is specified deep in the BGP specs and just wasn't implemented in v6?