From 6ebb8cd26962b9840a912d5fb0ab2d891f7b00e2 Mon Sep 17 00:00:00 2001 From: Christian Breunig Date: Mon, 11 Aug 2025 20:25:24 +0200 Subject: bond: T7571: fix inconsistent MAC address behaviour After upgrading from VyOS 1.3 to 1.4, there is an inconsistent behavior with MAC address assignment on bonded interfaces. In VyOS 1.3, bond interfaces used a hardware MAC address from one of the member interfaces. In 1.4, a synthetic MAC is used by default - generated by the Linux Kernel. Oddly, setting mode 802.3ad (which is also the default) temporarily causes the hardware MAC to be used again - until a reboot, after which the synthetic MAC returns. Deleting the mode config again causes the hardware MAC to be used. This inconsistent behavior has caused issues with MAC-based filtering in networks. The fix is to retrive the hardware MAC address from the first bond member interface and use set it explicitly for the bond interface. --- python/vyos/ifconfig/bond.py | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'python') diff --git a/python/vyos/ifconfig/bond.py b/python/vyos/ifconfig/bond.py index 8a97243c5..ba31ae0c9 100644 --- a/python/vyos/ifconfig/bond.py +++ b/python/vyos/ifconfig/bond.py @@ -485,11 +485,25 @@ class BondIf(Interface): # Add (enslave) interfaces to bond value = dict_search('member.interface', config) + is_first = True for interface in (value or []): - # if we've come here we already verified the interface - # does not have an addresses configured so just flush - # any remaining ones - Interface(interface).flush_addrs() + # Physical bond member interface instance + tmp_if = Interface(interface) + # At this point, we've confirmed that the interface has no + # configured addresses, so we can safely flush any remaining ones. + tmp_if.flush_addrs() + + # T7571: This behavior changed from Linux Kernel 5.4 (used in VyOS 1.3) + # to Kernel 6.6 (starting with VyOS 1.4). Previously, the MAC address of + # the first member interface in a bond was adopted as the bond's default MAC. + # In newer versions, a synthetic MAC address is assigned instead. + # + # Re-assign first underlay MAC address to the bond + if is_first: + self.set_mac(tmp_if.get_mac()) + is_first = False + + # Assign underlaying interface to logical bond self.add_port(interface) # Add system mac address for 802.3ad - default address is all zero -- cgit v1.2.3