Hi all,
we experienced issues with non-functional BFD Sessions. Debugging
yielded that bird does not use RFC compliant BFD Port ranges.
RFC 5881 states: "" The source port MUST be in the range 49152 through
65535. ""; however, the port range is not restricted within bird and
thus using arbitrary high ports.
Some tier 1 transit providers like "Deutsche Telekom" apply strict
filter for BFD and only allow RFC5881 compliant ports, hence the issue.
There is a workaround to limit the port range globally at system level
(/proc/sys/net/ipv4/ip_local_port_range); this seems to work, but we
have the strong feeling that restriction of port range for BFD sessions
should happen within bird itself.
Kind regards,
Christian
- Bird BFD is not compliant to RFC5881 Christian Bruns
-