I have a simple BGP setup where I'm seeing continual re-announcements of a prefix (every second or so) on 6.1.

Network could be shown as this:

<quagga AS1> ---- <mikrotik1 AS2> ---- <mikrotik2 AS2>

The Mikrotiks run iBGP between them, and the Quagga box only talks to one of the Mikrotiks. The Mikrotiks also use BGP for VPLS.

I see repeated BGP UPDATE announcements from Mikrotik1 to the Quagga box. Just updates, just one NLRI, no change in any BGP attribute. No other prefixes have this repeated announcement issue. Routing otherwise works fine and there is no problem receiving or sending any other routes.

I don't know if the Mikrotiks send the repeated updates between each other.

Both Mikrotiks originate a prefix defined in /bgp network. No BGP filtering on the Mikrotiks, although I do have a route filter on the iBGP session that sets the next hop to the loopback address on the router originating the route. I don't do this for outside routes.

I'm glad to provide more information if this isn't enough to reproduce.