Receive/export route limit behaviour?

[Guillaume LUCAS]

Hellow,

On my BIRD router, I have two IPv4 BGP upstream neighbors. From them, my
router receive 678,000 and 681,000 routes. On these BGP sessions, I have
configured "receive limit 700000 action block".

On this same router, I have one IPv4 BGP downstream neighbor. On this
one, I have configured "export where proto = "static_allocations" ||
proto = "bgp_upstream1" || proto = "bgp_upstream2";" and "export limit
700000 action disable". "static_allocations" always contains only one route.

BIRD frequently disables downstream neighbor's BGP session because the
export limit has been exceeded. I can understand this behaviour:
upstream1 may distribute routes that upstream2 does not have, but I see
the same behavior with "export limit 750000 action disable". However, my
upstreams do not provide me more than 50,000 different routes:

  # birdc sh route protocol bgp_upstream1 | grep -Po "[0-9./]+(?=[
]+via)" | sort -n > bgp_upstream1
  # birdc sh route protocol bgp_upstream2 | grep -Po "[0-9./]+(?=[
]+via)" | sort -n > bgp_upstream2
  # diff -b -w -y --suppress-common-lines bgp_upstream1 bgp_upstream2 |
wc -l
  3503

How is it possible to export more routes than I receive?

In IPv6, with the same upstream and downstram neighbors and "receive
limit" set to 50,000 and "export limit" set to 50,000, I have no problem.

Regards.