Who are the upstreams for AMPRNet?
I happened to be poking through the AMPRNet gateway list today, and pretty much out of nowhere came up with the question: I wonder what networks most commonly house AMPR gateways?
So, in this short post, I shall set out to answer that question.
A brief overview
Feel free to read about AMPRNet yourself online. There's lots of great information floating around.
For anyone looking for a TLDR before continuing, you can basically think of AMPRNet as an ad-hoc mesh of gateways that act as core routers for tiny slices of IP space. These gateways share routing information with each other and form a mixed-topology network that spans the globe.
What gateways exist?
Firstly, in order to figure out what networks house gateways, I need to know what gateways exist.
AMPR operators have access to a little API that allows us to query for a list of all active gateways, so thats where I shall start.
If you happen to be following along at home, heres the commands I am using to get my list of gateway IPs:
AMPR_API_TOKEN="your-api-token-here"
http get https://portal.ampr.org/api/v1/encap/routes \
"Authorization: Bearer $AMPR_API_TOKEN" \
"Accept: application/json" \
| jq ".encap[].gatewayIP" \
| tr -d '"' \
| sort \
| uniq
This returns a nicely sorted list of approximately 650 unique gateways.
Where are they?
Now that I have a list of IPs, I just put them into a file (/tmp/ips
in my case) and asked the BGP.tools API for info about them.
echo "begin\n$(cat /tmp/ips)\nend" | nc bgp.tools 43 | tee /tmp/bgp-tools-result
This gives me a very long list of ASNs for each gateway, which I can then process.
Taking the /tmp/bgp-tools-result
file that the previous command generated, I can now run the following command to get a list of unique ASNs:
cat /tmp/bgp-tools-result \
| cut -d "|" -f 7 \
| sort \
| uniq -c \
| sort -n -r
The results
At the time of writing, here's the distribution of gateways by Autonomous System:
Count | Autonomous System |
---|---|
46 | Comcast Cable Communications, LLC |
25 | Charter Communications Inc |
23 | The Constant Company, LLC |
23 | AT&T Services, Inc. |
22 | Verizon Business |
16 | Charter Communications |
15 | Akamai (Linode) |
14 | Free SAS |
11 | Amazon.com, Inc. |
10 | Lumen (ex. Qwest) |
10 | Cox Communications Inc. |
10 | Bell Canada |
9 | Ote SA (Hellenic Telecommunications Organisation) |
9 | DigitalOcean LLC |
249 | Various Others |
Note: the Various Others row represents nearly 230 ASes that only host 1 gateway, and a smaller handful that host a few more.