We maintain a set of informational and control communities to be used by network operators to influence their routing within our network. Control communities can only be used by customers. They will be filtered out on peering sessions.
Informational communities are filtered out on all BGP sessions.
Route source | Default Localpref | Community |
---|---|---|
Originated by AS394177 | N/A | 394177:101:1 |
Learned from Direct Peer | 130 | 394177:101:2 |
Learned from IX Routeserver | 120 | 394177:101:3 |
Learned from Transit | 100 | 394177:101:4 |
Learned from Customer | 140 | 394177:101:5 |
Location learned | Community |
---|---|
Learned in Dallas | 394177:102:1 |
Learned in Atlanta | 394177:102:2 |
Learned in Chicago | 394177:102:3 |
We feed routes to many community-run BGP looking glass services including bgp.tools and lg.ring.nlnog.net. We send these services multiple routes we hold in each location, even though only one is active. The following BGP communities indicate which route is active within our network at a given location.
Location | Community |
---|---|
Active path in Dallas (DAL1, 1515 Round Table) | 394177:112:1 |
Active path in Atlanta | 394177:112:2 |
Active path in Chicago | 394177:112:3 |
Active path in Dallas (DAL2, 2323 Bryan St) | 394177:112:4 |
These communities can be used by customers to influence their routing within our network.
Action | Community |
---|---|
Prepend 394177 1x to ASXXXXX | 394177:51:XXXXX |
Prepend 394177 2x to ASXXXXX | 394177:52:XXXXX |
Prepend 394177 3x to ASXXXXX | 394177:53:XXXXX |
Do not export to ASXXXXX | 394177:50:XXXXX |
You may also use 2, 3, and 4 to specify all direct peers, route servers, and transits respectively. In addition, 0
can be used to specify all peers.
To modify exports to route servers of IXPs, you may use the following ASNs:
Internet Exchange | ASN |
---|---|
DE-CIX Dallas | 62499 |
Digital Realty Atlanta | 32299 |
DE-CIX Chicago | 62760 |
You may use BGP communities to change a route’s Local Preference within our network.
Local Preference | Community |
---|---|
90 (Below transit) |
394177:2:90 |
100 (Same as transit) |
394177:2:100 |
110 (Above transit, below peering) |
394177:2:110 |
120 (Same as RS Peers) |
394177:2:120 |
130 (Same as Direct Peers) |
394177:2:130 |
135 (Above all peering/transit, below customers) |
394177:2:135 |
140 (Same as customers) |
394177:2:140 |
150 (Above customers) |
394177:2:150 |
We allow customers to blackhole any prefix up to a /32 IPv4 and /128 IPv6 on our network using a BGP community. Alongside discarding traffic to the prefix/IP on our routers, applying this community to a route also applies an equivalent community for upstream transit providers that support blackhole by BGP community.
394177:666:0
We operate a backbone of 10G waves or better between all of our locations. We understand that having traffic traverse this backbone may be undesirable for some customers. As such we provide the following communities to control announcements to other locations.
Action | Community |
---|---|
Do not export in Dallas | 394177:32:1 |
Do not export in Atlanta | 394177:32:2 |
Do not export in Chicago | 394177:32:3 |
Do not advertise to other locations | 394177:77:0 |
⚠️ If you do not have transit other than AS394177,
394177:77:0
may break connectivity in unexpected ways
We modify our routing using BGP communities and other fields to ensure optimal latency. This may be undesirable for some customers. Permanent traffic engineering actions that can be changed by customers are listed below.
Default action | Community | New action |
---|---|---|
Tag routes announced to Cogent AS174 with community 174:991 (only announce to internal + customers) |
394177:505:174 |
Remove this community, allowing the route to be announced to all peers and the greater internet by Cogent. |
Tag routes announced to Lumen AS3356 with community 65000:20940 (do not announce to AS20940, Akamai) |
394177:505:20940 |
Removes this community, allowing Lumen to announce the route to Akamai AS20940 |