The Echo Service

What is the

The Echo Service?

Service

The Torus Echo Service is a lightweight connectivity test running on the meshfirst atthing 10.254.100.102.to try when troubleshooting connectivity. If you can reach it, you are connected to the Torus.

It serves three purposes:

• Reachability check — confirms your WireGuard tunnel is upworking.
  and routing correctly
• Latency measurement — measures round-trip time between your device and the London hub
• Interactive echo — a telnet service that reflects everything you type, useful for verifying bidirectional data flow

How to Use It

Web Browser

Open http://10.254.100.102echo.ring.nekotopia.io in your browser. You should see a dark-themed page with a pulsing green ring and the text “"Connected to Torus”Torus".

The page displays:

the

Field	Description
Status	Shows reachable if you can communicate with the echo node
Your IP	Your WireGuard tunnel IP address (e.g. 10.254.100.109)
Echo node	The echo service’s address: 10.254.100.102
Hub	The hub hosting the echo service (London, eu-west-2)
Latency	Measured round-trip time (average of 4 samples)
Telnet	Address for

interactive echo service

Ping Test

From any terminal on the Torus:

ping 10.254.100.102echo.ring.nekotopia.io

Expected output for a London-connected user:

PING 10.254.100.102 (10.254.100.102):echo.ring.nekotopia.io: 56 data bytes
64 bytes from 10.254.100.102:echo.ring.nekotopia.io: icmp_seq=0 ttl=64 time=12.3 ms

Telnet Echo

The telnet service on port 23 echoes back everything you type — a classic connectivity test that confirms bidirectional data flowflow:

through the tunnel:

telnet 10.254.100.102echo.ring.nekotopia.io

You willYou'll see a welcome banner with your tunnel IP address. Type anything and it will beit's reflected back to you.back. To exit, press Ctrl+Ctrl+] then type quit.

This is particularly useful for testing from retro or legacy systems that may not have a web browser or curl available.

API Endpoint

The echo service exposes a JSON endpoint at /ping:

curl http://10.254.100.102/echo.ring.nekotopia.io/ping

Response:Returns JSON:

{"status":"ok","remoteIp":"10.254.100.109","rtt":"0.01","node":"10.254.100.102","hub":"eu-west-2"}

ExpectedIf LatencyYou Cannot Reach It

Your measured

latency
1. Check dependsVPN is connected — run sudo wg show and verify the handshake is recent (within 2-3 minutes)
2. Try by IP — ping 10.255.137.222. If this works but the hostname doesn't, your DNS is not using the tunnel's DNS server
3. Check AllowedIPs — your WireGuard config must include 10.254.0.0/16 and 10.255.0.0/16
4. Edge router users — ensure your router has masquerade NAT for LAN traffic going out the WireGuard interface
5. Firewall — allow outbound UDP on yourport physical13231
distance

from

For thea Londonfull hub:

Location	Expecteddiagnostic RTT
London / UK	5–15 ms
Continental Europe	20–40 ms
US East Coast	70–90 ms
Middle East (Dubai)	100–130 ms
US West Coast	130–160 ms
Asia Pacific	150–250 ms

Troubleshooting

If the echo service is unreachable,walkthrough, see the Connection Issues.

page

More inabout thisDNS

book

All .ring.nekotopia.io hostnames (including echo.ring.nekotopia.io) resolve automatically when you're connected to the Torus. Your WireGuard config includes the DNS server. See DNS and Network Services for athe step-by-stepfull diagnostichostname guide.list and troubleshooting.