Trippy 0.13.0

Highlights

The 0.13.0 release of Trippy includes several enhancements related to Type of Service (ToS) and adds new Dscp and Ecn columns.

It also includes improvements to the TUI such as allowing a custom timezone to be set and adding the ability to read the configuration file from the XDG app config directory. The json report has been enriched with start and end timestamps.

This release includes a number of bug fixes. For Windows users in particular, this release includes several important stability improvements.

The release also introduces a new system address family option, which will become the new default in the next major release.

Finally, Trippy now has a dedicated website and a logo!

Type of Service (DSCP/ECN) Improvements

Trippy allows setting the Type of Service (ToS) for IPv4 via the --tos (-Q) command-line argument (or via the configuration file). The ToS value is the second byte of the IPv4 header and encodes the Differentiated Services Code Point (DSCP) and Explicit Congestion Notification (ECN) fields.

Setting the ToS on outgoing probe packets can influence the Quality of Service (QoS) used by the network devices along the path.

Probe responses received from the hops along the path include the ToS values in the Original Datagram (the IPv4/IPv6 header of the probe packet nested inside the ICMP error). Examining the ToS value from the Original Datagram can provide useful insight into the QoS treatment of the probe packets by network devices along the path.

This release of Trippy adds two new columns to display the DSCP & ECN values, which are derived from the ToS value from the Original Datagram for each hop. The new columns are:

• Dscp (K): The Differentiated Services Code Point (DSCP) of the Original Datagram for a hop
• Ecn (M): The Explicit Congestion Notification (ECN) of the Original Datagram for a hop

The Dscp and Ecn columns are decoded from the ToS field of the Original Datagram. If no ToS value is present, then the columns will show na. Note that these columns show the most recent ToS value received from the hop and may therefore change between rounds.

Well-known DSCP values are displayed as follows:

• Default Forwarding (DF) aka Best Effort aka Class Selector 0 (CS0)
• Assured Forwarding (AFn)
• Class Selector (CSn)
• High Priority Expedited Forwarding (EF)
• Voice Admit (VA)
• Lower Effort (LE)

Unknown DSCP values are displayed as a hexadecimal value.

The ECN value is displayed as follows:

• Not ECN-Capable Transport (NotECT)
• ECN Capable Transport(1) (ECT1)
• ECN Capable Transport(0) (ECT0)
• Congestion Experienced (CE)

These columns are hidden by default but can be enabled as needed. For more details, see the Column Reference.

The following example sets the ToS to be 224, which is a DSCP value of CS7 (0x38) and an ECN value of NotECT (0x0), and enables the new columns:

trip example.com --tos 224 --tui-custom-columns holsravbwdtKM

The following screenshot shows the example trace:

The ToS field of the Original Datagram has also been added to the json output format as a decimal value.

See #1539 for details.

This release also adds support for setting the IPv6 Traffic Class (which encodes the DSCP & ECN values in the same way as IPv4) via the same --tos (-Q) command-line argument (or via the configuration file). Note that setting the IPv6 Traffic Class is not currently supported on Windows. See #202 for details.

Finally, a bug which caused the --tos (-Q) command-line argument to be ignored for IPv4/UDP tracing has been fixed in this release. See #1540 for details.

Custom TUI Timezone

Trippy shows the wall-clock time in the header of the TUI. Currently, this is set to show the local timezone of the system running Trippy. This can be problematic for users who are running Trippy in a container or on a remote system that uses a different timezone.

This release adds the ability to set a custom timezone for the TUI using the --tui-timezone command-line argument (or via the configuration file). The timezone can be set to any valid IANA timezone identifier, such as UTC, America/New_York, or Europe/London.

The following example sets the timezone to UTC:

trip example.com --tui-timezone UTC

This can be made permanent by setting the tui-timezone value in the tui section of the configuration file:

[tui]
tui-timezone = "UTC"

See #1513 for details.

XDG App Config Directory

Trippy will now attempt to locate a trippy.toml or .trippy.toml config file in the XDG app config directory (i.e. $XDG_CONFIG_HOME/trippy or ~/.config/trippy) in addition to existing locations.

This allows users to store their Trippy configuration files in a dedicated directory for Trippy, separate from other applications.

The full list of locations Trippy will check for a trippy.toml or .trippy.toml config file is as follows:

• the current directory
• the user home directory
• the XDG config directory (Unix only): $XDG_CONFIG_HOME or ~/.config
• the XDG app config directory (Unix only): $XDG_CONFIG_HOME/trippy or ~/.config/trippy
• the Windows data directory (Windows only): %APPDATA%

See #1528 for details.

System Address Family

Trippy supports tracing for both IPv4 and IPv6 address families. If the tracing target is supplied as a hostname, Trippy will attempt to resolve the hostname to a single IPv4 or IPv6 address. If the hostname resolves to both, Trippy will use the address family (--addr-family) configuration to determine which address family to use.

The possible values for --addr-family are:

• ipv4 - Lookup IPv4 only
• ipv6 - Lookup IPv6 only
• ipv6-then-ipv4 - Lookup IPv6 with a fallback to IPv4
• ipv4-then-ipv6 - Lookup IPv4 with a fallback to IPv6 [default]

The current default value for --addr-family is ipv4-then-ipv6, which means that if the hostname resolves to both IPv4 and IPv6 addresses, Trippy will prefer the IPv4 address family.

Some users find the default behavior undesirable, as it can lead to unexpected results when the hostname resolves to a different address family than the one used by other applications on the system.

This release adds a new value for --addr-family called system. This value defers the choice of address family to the first address returned by OS resolver. This means that if the hostname resolves to both IPv4 and IPv6 addresses, the OS resolver will determine which address family to use based on the OS configuration.

Note that if the --addr-family value is set to system and the --dns-resolve-method is set to any value other than system (i.e. resolv, cloudflare or google), then the address family lookup will effectively default to ipv6-then-ipv4.

Important: The default value for --addr-family will change to become system in the next major release of Trippy (0.14.0). This will be a breaking change for users who rely on the current default value of ipv4-then-ipv6.

See #1469 for details.

Remove Address Family "downgrade" for Dublin Strategy

Currently, the address families ipv4-then-ipv6 and ipv6-then-ipv4 are silently downgraded to ipv4 when the dublin ECMP strategy is used. This behaviour was previously necessary, as Trippy did not support the dublin ECMP strategy for IPv6. However, Trippy has supported the dublin ECMP strategy for IPv6 since version 0.10.0. As a result, this release removes the address family downgrade for the dublin ECMP strategy.

See #1476 for details.

Windows Stability Improvements

This release includes several stability improvements for Windows. It fixes several known or potential issues that could cause crashes or memory corruption. It is recommended that all Windows users upgrade to this release.

See the following issues for details:

• Memory corruption on Windows (#1527)
• Socket being closed twice on Windows (#1443)
• Potential crash on Windows for adapters without unicast addresses (#1547)
• Potential use-after-free when discovering source address on Windows (#1558)

Start and End Timestamps in JSON report

The Trippy json report mode has been enhanced to show the start and end timestamps for the trace. These timestamps are shown in UTC using RFC 3339 format.

The following example runs a trace to example.com for a single round and outputs the results in json format:

trip example.com -m json -C 1

The info section of the output now includes the start_timestamp and end_timestamp fields:

{
  "info": {
    "target": {
      "ip": "23.192.228.80",
      "hostname": "example.com"
    },
    "start_timestamp": "2025-05-04T09:50:10.383221Z",
    "end_timestamp": "2025-05-04T09:50:11.392039Z"
  }
}

See #1510 for details.

Reduce Tracing Verbosity

The trippy-core crate logging is overly verbose. This release reduces all #[instrument] annotations from the default info level to the trace level. It also removes some tracing annotations and, in some cases, adds new ones.

There are now no info level logs and only a handful of debug level logs:

• Log the channel config when a channel is created (typically just once)
• Log the strategy config when the tracer is started (typically just once)
• Log each probe sent and received during a round (typically a handful per round)

For application users there is no change; however the default logging level (--log-filter trippy=debug) used when -v is passed will now show substantially fewer logs. Users can set --log-filter trippy=trace to see a logging level similar to the previous default.

See #1482 for details.

Bug Fixes

This release fixes a bug where ICMP packets larger than 256 bytes could cause a tracer panic. See #1561 for details.

It also adds a handful of missing configuration options to the settings dialog. See #1541 for details.

Trippy Website & Logo

Trippy now has a dedicated website: https://trippy.rs

The website is now the primary source of documentation. My thanks to @orhun for building the https://binsider.dev website which I took inspiration from shamelessly copied for Trippy.

Along with the new website, Trippy (finally!) has a logo:

With thanks to Harun Ocaksiz Design.

See #100 for details.

New Distribution Packages

Trippy has been added to the Void Linux package repository (with thanks to @icp1994!):

xbps-install -S trippy

Trippy was also added to ALT Sisyphus package repository (with thanks to Aleksandr Voyt!)

apt-get install trippy

Finally, Trippy has been added to the Chimera Linux package repository (with thanks to @ttyyls!):

apk add trippy

Thanks

My thanks to all Trippy contributors, package maintainers, translators and community members.

Feel free to drop by the Trippy Zulip room for a chat:

Happy Tracing!

Change Log

Added

• Added DSCP and ECN columns (#1539)
• Added support for setting IPv6 traffic class from --tos (#202)
• Added ability to read config from $XDG_CONFIG_HOME/trippy directory (#1528)
• Added --tui-timezone flag to set a custom timezone (#1513)
• Added support for --addr-family system to defer address family selection to the OS resolver (#1469)
• Added tracing start and end timestamps to the json report (#1510)
• Added the Trippy logo! (#100)

Changed

• Remove address family downgrade for dublin strategy (#1476)
• Reduce verbosity of tracing for library users (#1482)
• Increase MSRV to 1.78 (#1576)

Fixed

• Tracer panic for large icmp packets (#1561)
• Memory corruption on Windows (#1527)
• Socket being closed twice on Windows (#1443)
• Potential crash on Windows for adapters without unicast addresses (#1547)
• Potential use-after-free when discovering source address on Windows (#1558)
• The --tos (-Q) flag is ignored for IPv4/udp tracing (#1540)
• Items missing from settings dialog (#1541)

See CHANGELOG.md for details.

Full Changelog: 0.12.2...0.13.0