ttl

Modern traceroute/mtr-style TUI with hop stats and optional ASN/geo enrichment.

Features

• Fast, low-overhead continuous path monitoring
• Useful hop-level stats (loss, min/avg/max, jitter, stddev)
• Great terminal UX built with ratatui
• Scriptable mode for CI and automation
• Reverse DNS resolution
• ECMP detection (multiple responders per TTL)
• Multiple export formats (JSON, CSV)
• Session replay from saved JSON files
• IPv4 and IPv6 support

Installation

From source

cargo install --git https://github.com/lance0/ttl

Permissions

Raw sockets require elevated privileges. Choose one:

# Option 1: Run with sudo
sudo ttl 1.1.1.1

# Option 2: Add capability (Linux)
sudo setcap cap_net_raw+ep $(which ttl)

# Option 3: Enable unprivileged ICMP (Linux)
sudo sysctl -w net.ipv4.ping_group_range='0 65534'

Platform Support

Usage

Interactive TUI (default)

ttl 1.1.1.1
ttl google.com

Report mode

ttl 1.1.1.1 -c 100 --report

JSON export

ttl 1.1.1.1 -c 100 --json > results.json

CSV export

ttl 1.1.1.1 -c 100 --csv > results.csv

Replay a saved session

ttl --replay results.json --report
ttl --replay results.json           # opens in TUI

Streaming output

ttl 1.1.1.1 --no-tui

Options

-c, --count <N>      Number of probes (0 = infinite, default)
-i, --interval <S>   Probe interval in seconds (default: 1.0)
-m, --max-ttl <N>    Maximum TTL (default: 30)
--timeout <S>        Probe timeout in seconds (default: 3)
-4, --ipv4           Force IPv4
-6, --ipv6           Force IPv6
--no-dns             Skip reverse DNS lookups
--no-tui             Streaming output mode
--report             Batch report mode (requires -c)
--json               JSON output (requires -c)
--csv                CSV output (requires -c)
--replay <FILE>      Replay a saved JSON session
--theme <NAME>       Color theme (see Themes section)

Keybindings

Themes

11 built-in themes are available. Set via --theme flag or cycle with t key in the TUI.

# Start with a specific theme
ttl 1.1.1.1 --theme dracula

# Press 't' during runtime to cycle themes

Troubleshooting

Permission errors

Error: Insufficient permissions for raw sockets

Raw ICMP sockets require elevated privileges. See the Permissions section above.

High packet loss

If you see high loss (>10%) to a destination that should be reachable:

1. Network congestion - Some routers deprioritize ICMP traffic
2. Rate limiting - Target may rate-limit ICMP responses
3. Firewall - Intermediate firewalls may drop ICMP
4. ECMP paths - Multiple paths with different characteristics

Try increasing the probe interval: ttl target -i 2.0

All hops showing * * *

This usually means:

1. Firewall blocking - Your outbound ICMP is blocked
2. VPN interference - Some VPNs don't pass ICMP correctly
3. Target unreachable - Verify the IP/hostname is correct

IPv6 not working

1. Verify IPv6 connectivity: ping6 2001:4860:4860::8888
2. Force IPv6: ttl -6 google.com
3. Check if your ISP supports IPv6

DNS resolution slow

Reverse DNS lookups can be slow. Disable with --no-dns for faster startup.

Tech Stack

• Language: Rust
• TUI: ratatui + crossterm
• Async: tokio
• Sockets: socket2 + pnet
• DNS: hickory-resolver

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.