From f077a176024d8b4afcef21bf20314acb6095b2d1 Mon Sep 17 00:00:00 2001 From: Joerg Hofrichter Date: Tue, 28 May 2024 15:58:38 +0200 Subject: [PATCH] mpm: deactivate Duplicate Address Detection (DAD) on int0 interface Starting from systemd v245, Duplicate Address Detection (DAD) is automatically enabled for static IPv4 addresses if the IP address is a link local address. DuplicateAddressDetection=none (or DuplicateAddressDetection=true for historical reasons) deactivates this. Important notes on compatibility: - systemd v243.2 (Yocto release zeus) does not support DuplicateAddressDetection=none and errors out without applying the IPv4 address -> use the historical parameter DuplicateAddressDetection=true to remain backward compatibility - systemd v250.5 (Yocto release kirkstone) ignores the DuplicateAddressDetection=none (or DuplicateAddressDetection=true) parameter for link local addresses and enables DAD unconditionally. This is fixed by commit a9efd16090baee492e9dd9ae832b5b548e7c6fcf ("network: do not enable IPv4 ACD for IPv4 link-local address if ACD is disabled explicitly") which is not part of default Yocto systemd v250.5. In meta-ettus we have applied the patch so that the DuplicateAddressDetection=none (or DuplicateAddressDetection=true) parameter is honored for link local addresses --- mpm/systemd/network/int0.network | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mpm/systemd/network/int0.network b/mpm/systemd/network/int0.network index 67a04c322..79e352b2b 100644 --- a/mpm/systemd/network/int0.network +++ b/mpm/systemd/network/int0.network @@ -2,8 +2,13 @@ Name=int0 [Network] -Address=169.254.0.1/24 IPForward=ipv4 +[Address] +Address=169.254.0.1/24 +# The setting actually means DuplicateAddressDetection=none. We use the old flag here +# on purpose to remain backward compatibility with systemd v243.2 (Yocto release zeus) +DuplicateAddressDetection=true + [Link] MTUBytes=9000