●Change8

Migrating to Linkerd edge-25.3.2

Version edge-25.3.2 introduces 2 breaking changes. This guide details how to update your code.

Released: 3/14/2025

2
Breaking Changes
2
Migration Steps
4
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

protocol detection proxyoutbound-transport-modeGateway API CRDsinbound server metrics

Breaking Changes

●Issue #1

The default for `outbound-transport-mode` is now `transport-header`. This means all traffic between meshed proxies flows over port 4143 instead of the original destination port, which might break clients expecting traffic on the original port.

●Issue #2

If a client closes a connection without writing any data, the protocol detection proxy treats this as a read failure. Clients using unusual half-open connections might see behavioral changes; such clients may need to have their connections marked as opaque.

Migration Steps

  1. 1
    If you have clients that rely on connections being open without data being sent (half-open connections), consider marking those connections as opaque due to changes in protocol detection behavior.
  2. 2
    Review configurations if relying on inter-proxy traffic using original destination ports, as the default `outbound-transport-mode` is now `transport-header` (using port 4143).

Release Summary

This release changes the default for `outbound-transport-mode` to `transport-header` and fixes an issue with Helm installing Gateway API CRDs incorrectly. It is strongly recommended to use edge-25.7.4 instead due to known issues, including lack of IPv6 support.

Need More Details?

View the full release notes and all changes for Linkerd edge-25.3.2.

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