Blackholing

Pathvector supports remotely triggered blackholing (RTBH).

Accepting blackhole requests from a peer

Set allow-blackhole-community: true on a peer to let it request blackholing. A route is treated as a blackhole request when it carries the large community (<your ASN>, 1, 666) and is a host route (/32 for IPv4 or /128 for IPv6). Matching routes get their next hop rewritten to a null route (192.0.2.1 / 100::1, which are installed as blackhole routes in BIRD).

Blackhole requests are by definition more specific than the filter-prefix-length bounds (IPv4 /8-/24, IPv6 /12-/48), so when allow-blackhole-community is enabled, blackhole requests skip the prefix length check. Every other import filter (bogons, RPKI, IRR, prefix sets, AS sets, ...) still applies to them.

peers:
  Customer:
    asn: 65510
    neighbors:
      - 192.0.2.10
    allow-blackhole-community: true

Blackholing all routes from or to a peer

• blackhole-in blackholes every route imported from the peer.
• blackhole-out blackholes every route exported to the peer.