Add 'min-version' RTR config option and default to RTR version 1 by default.

The min-version pins a minimal required version for rtr session. This is
needed if specific PDUs are required and it ensures that the session is
not suddenly downgraded. This is important for ASPA where a minimum
version of 2 is required. Only then the ASPA PDUs are transmitted.

By default a RTR version of 1 is used but setting min-version to 2
will enable draft-ietf-sidrops-8210bis-14 support and enforce it
at the same time. Right now defaulting to version 2 is not possible
since draft-ietf-sidrops-8210bis failed to progress for a too long
time resulting in split eco system with various incompatible RTR
version 2 implementations.

OK tb@

1 files changed, 8 insertions, 2 deletions

diff --git a/usr.sbin/bgpd/bgpd.conf.5 b/usr.sbin/bgpd/bgpd.conf.5
index a554e51ffb6..e01abf88b76 100644
--- a/usr.sbin/bgpd/bgpd.conf.5
+++ b/usr.sbin/bgpd/bgpd.conf.5
@@ -1,4 +1,4 @@
-.\" $OpenBSD: bgpd.conf.5,v 1.240 2024/04/24 10:41:34 claudio Exp $
+.\" $OpenBSD: bgpd.conf.5,v 1.241 2024/08/12 09:04:23 claudio Exp $
 .\"
 .\" Copyright (c) 2004 Claudio Jeker <claudio@openbsd.org>
 .\" Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -16,7 +16,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: April 24 2024 $
+.Dd $Mdocdate: August 12 2024 $
 .Dt BGPD.CONF 5
 .Os
 .Sh NAME
@@ -579,6 +579,12 @@ Bind to the specific IP address before opening the TCP connection to the
 .Em rtr
 server.
 .Pp
+.Ic min-version Ar number
+Require a minimal RTR version of
+.Ar number .
+To ensure that ASPA records are synchronised over RTR a minimal version
+of 2 is required.
+.Pp
 .It Ic port Ar number
 Specify the TCP destination port for the
 .Em rtr