BGP Communities

If you announce your own prefixes to CubePath (AS26141) — over an IP Transit port or a tunnel — you can attach standard BGP communities in the form 26141:XXXXX to control how we handle your route.

Communities are processed in this order:

1. Local preference from customer action communities
2. No-export communities decide which providers must not receive the prefix
3. Selective export overrides force export despite a no-export tag
4. Prepending communities shape inbound traffic
5. Blackhole communities trigger RTBH if present

Note

Customer routes always receive the highest local preference in our network (200) and are always preferred over transit, IXP or PNI routes.

Network locations

Local preference

Use 26141:8000 on a backup site so only its own continent uses it, and 26141:8090 to make a session the last-resort path everywhere.

Blackhole (RTBH)

Blackhole announcements must be /32 (IPv4) or /128 (IPv6), and must be covered by a less-specific prefix you already announce. Propagated to Cogent (AS174), Lumen (AS3356), GTT (AS3257) and NEAR IP (AS49600).

DDoS scrubbing

The difference from blackholing is the whole point: blackhole drops all traffic and the IP goes dark, while scrubbing filters attack traffic and keeps delivering legitimate traffic, so the IP stays reachable.

Note

CubePath mitigates volumetric attacks locally with no community required. 26141:112 is for deeper inline inspection, and is available only on the AntiDDoS Premium plan.

No multihoming

By default your prefixes are announced from every CubePath site. These restrict that:

Strict is the one for data-residency or geographic compliance requirements. Relaxed keeps internal connectivity to other sites without external announcement.

Note

No-multihoming mode is configured at the service level — contact support to enable or change it.

No-export

By transit provider: 30010 NEAR IP · 30020 Lumen · 30030 Cogent · 30040 GTT.

By IXP: 40010 FL-IX · 40020 Inter-IX · 40030 Speed-IX · 40040 Frys-IX · 40050 PiterIX-FRA · 40060 PiterIX-MSK · 40070 PiterIX-SPB · 40080 DE-CIX Barcelona.

By continent: 51000 Europe · 52000 North America. By country/state: 51010 Spain · 51020 Netherlands · 52010 Texas · 52020 Florida · 52030 Virginia.

Selective export override

These override a no-export tag, so you can suppress broadly and still allow one provider. They do nothing on their own.

Force export to a transit: 9121 NEAR IP · 9122 Lumen · 9123 Cogent · 9124 GTT. Force export to an IXP: 9111 FL-IX · 9112 Inter-IX · 9113 Speed-IX · 9114 Frys-IX · 9115 PiterIX-FRA · 9116 PiterIX-MSK · 9117 PiterIX-SPB · 9118 DE-CIX Barcelona.

AS-path prepending

Prepending makes your path look longer so remote networks prefer another route. The last digit is the number of prepends (1, 2 or 3) throughout.

MED

CubePath honours your MED and never modifies it on inbound; it's preserved across our network. Lower MED is more preferred.

Since all customer routes carry local-pref 200, MED is the tiebreaker between multiple paths from the same customer — which makes it the cleanest way to express "prefer Miami, fall back to Houston" when you're multi-homed to us at several sites.

Worked examples

Getting help

Traffic engineering is easy to get subtly wrong, and a bad community combination is usually invisible from your side — the prefix simply stops appearing where you expected. If a change does not behave the way this page describes, open a support ticket with the prefix, the communities you attached and the session it was announced from, and we will look at what our routers actually received.