On Thu, Jan 29, 2026 at 12:05:00PM +0100, Sebastian Andrzej Siewior wrote:

On 2026-01-22 15:56:56 [+0100], Felix Maurer wrote:

quoted

diff --git a/tools/testing/selftests/net/hsr/prp_ping.sh b/tools/testing/selftests/net/hsr/prp_ping.sh
new file mode 100755
index 000000000000..fd2ba9f05d4c
--- /dev/null
+++ b/tools/testing/selftests/net/hsr/prp_ping.sh

…

quoted

+	# MAC addresses will be copied from LAN A interface
+	ip -net "$node1" link set address 00:11:22:00:00:01 dev vethA
+	ip -net "$node2" link set address 00:11:22:00:00:02 dev vethA

so I somehow started this (I think) but while browsing the spec it
somehow says that the same MAC address should be used on both ports.
Could it be?
It says that the two frames are identical except for the LAN field and
checksum. Also the duplication is defined on src-MAC + seq nr.
Having this requires to merge the two MACs for a node and we do this but
could this be a left over from an older version of the spec or a
behaviour that was not meant happen?

Yes, for PRP it is required that both ports, A and B, of a node send
with the same MAC. For us that means that the two ports need to be
configured with the same MAC address. This used to be a common source of
configuration errors. Therefore, b65999e7238e ("net: hsr: sync hw addr
of slave2 according to slave1 hw addr on PRP") made it so that we are
now copying the MAC from port A to port B.

Therefore, I'm only setting the MAC of vethA on each node in the test.
Even this is not strictly necessary but it turns out that debugging is a
lot simpler, when it is obvious addresses belong to which node.

Thanks,
   Felix