Hello,
we are runnning about 20 switches in a complex VLAN and RSTP setup. Servers are using MLAG bondings.
Sometimes some servers are not available on some VLANs. IT seems to be an issue with the MAC-Adress learning, since the MAC is present on some switches. For example with MAC 04:F4:1C:C1:27:1B and VLAN 1150 and VLAN 2702 (Server is connected to 1.22-01 and 1.22-02 via MLAG):
Present on Switch 1.22-01:
# 2026-04-27 11:51:47 by RouterOS 7.20.7
# software id = HWG1-RLU3
#
Flags: X - disabled; I - invalid; D - dynamic; L - local; E - external
# MAC-ADDRESS VID ON- BR REMOTE-IP
0 DL 04:F4:1C:C1:20:51 bon br
...
379 D E 06:27:5D:CD:70:7B 1150 bon br
...
478 D E 06:27:5D:CD:70:7B 2702 bon br
...
and 1.22-02:
# 2026-04-27 11:52:02 by RouterOS 7.20.7
# software id = R03B-14QV
#
Flags: X - disabled; I - invalid; D - dynamic; L - local; E - external
# MAC-ADDRESS VID ON- BR REMOTE-IP
0 DL 04:F4:1C:C1:21:0F bon br
...
165 D E 06:27:5D:CD:70:7B 1150 bon br
...
216 D E 06:27:5D:CD:70:7B 2702 bon br
...
and 1.12-02:
# 2026-04-27 11:51:20 by RouterOS 7.20.7
# software id = 6CE1-ZVR9
#
Flags: X - disabled; I - invalid; D - dynamic; L - local; E - external
# MAC-ADDRESS VID ON- BR REMOTE-IP
0 DL 04:F4:1C:C1:27:1C bon br
...
215 D E 06:27:5D:CD:70:7B 1150 qsf br
...
299 D E 06:27:5D:CD:70:7B 2702 qsf br
...
but VLAN 1150 not on 1.12-01:
# 2026-04-27 11:51:34 by RouterOS 7.20.7
# software id = IWS4-UGS7
#
Flags: X - disabled; I - invalid; D - dynamic; L - local; E - external
# MAC-ADDRESS VID ON- BR REMOTE-IP
0 D E 04:F4:1C:C1:27:1B qsf br
...
480 D E 06:27:5D:CD:70:7B 2702 qsf br
...
All switches are running on 7.20.7 LTS version. The VLAN configuration between switches is OK. A reboot from the client machine does not work, but a reboot from the switch with missing MAC seems to work fine.
Is this a bug or have I misunderstood/misconfigured something?
Thanks!