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Connection Diagnostics

This guide explains how to observe active connections and verify peer connectivity using Fungi CLI.

Prerequisite: fungi daemon must be running.

Need binaries first? Start at Install Fungi.

Why This Matters​

When file transfer or tunneling behaves unexpectedly, these commands help you quickly answer:

  • Is the peer currently connected?
  • Are streams being created on expected protocols?
  • Is latency stable across active links?

Commands​

Fungi provides two diagnostics entry points:

  • fungi connection (alias: fungi conn) for connection and stream snapshots
  • fungi ping <peer_id> for continuous RTT checks on active links

Inspect Active Connections​

Show an overview of active connections:

fungi conn overview

Filter by peer:

fungi conn overview --peer-id 16Uiu2HAmXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Filter by protocol:

fungi conn overview --protocol-name /fungi/tunnel/8080/1.0.0

Use verbose output:

fungi conn overview --verbose

Inspect Active Streams​

List active streams:

fungi conn streams

Filter options are the same as overview:

fungi conn streams --peer-id 16Uiu2HAmXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
fungi conn streams --protocol-name /fungi/tunnel/8080/1.0.0
fungi conn streams --verbose

Inspect Relay Status​

List configured relay endpoints and their current health:

fungi conn relay-status

In relay status output, TCP endpoints should be the stable reservation/circuit carriers. UDP/QUIC endpoints may appear without a relay listener because Fungi uses them only as observer endpoints for UDP address refresh before hole punching.

Continuous Peer Ping​

Run continuous ping on all active connections to a peer:

fungi ping 16Uiu2HAmXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Set custom interval (milliseconds):

fungi ping 16Uiu2HAmXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --interval-ms 1000

Show detailed output:

fungi ping 16Uiu2HAmXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --verbose

Stop with Ctrl+C.

Practical Troubleshooting Flow​

  1. Run fungi conn overview to confirm the peer has active connections.
  2. Run fungi conn streams to verify stream activity on expected protocols.
  3. Run fungi ping <peer_id> to monitor RTT and check for intermittent instability.
  4. If there are no active connections, verify allowed peers and relay/network settings in your config.