From 7a511b8555bf1431bce45cebe1e9a5a9c3369c70 Mon Sep 17 00:00:00 2001 From: Vjaceslavs Klimovs Date: Sat, 13 Jun 2026 21:45:55 -0700 Subject: [PATCH] link: do not assign default MAC to NOARP interfaces --- libifstate/link/base.py | 6 ++++++ libifstate/netns/__init__.py | 1 + 2 files changed, 7 insertions(+) diff --git a/libifstate/link/base.py b/libifstate/link/base.py index 1b525b6..44299ab 100644 --- a/libifstate/link/base.py +++ b/libifstate/link/base.py @@ -552,6 +552,12 @@ class Link(ABC): master_item = self.ifstate.link_registry.get_link(index=master, netns=self.netns.netns) set_address = master_item.attributes['kind'] != 'bond' + # NOARP interfaces (e.g. layer-3 TUN) have no L2 address; the kernel + # rejects setting one, so a default MAC would make every apply report + # a spurious link change (never converging). + if item is not None and item.attributes.get('flags', 0) & IFF_NOARP: + set_address = False + if set_address: if self.settings['kind'] == 'physical': if item is not None and 'perm_address' in item.attributes: diff --git a/libifstate/netns/__init__.py b/libifstate/netns/__init__.py index b805b8b..eee5106 100644 --- a/libifstate/netns/__init__.py +++ b/libifstate/netns/__init__.py @@ -329,6 +329,7 @@ class LinkRegistryItem(): 'index': link['index'], 'ifname': link.get_attr('IFLA_IFNAME'), 'address': link.get_attr('IFLA_ADDRESS'), + 'flags': link['flags'], } self.registry = registry self.netns = netns -- 2.53.0