We have 2 x CSS326-24G-2S+RM that we are trying to extend a single VLAN with. Everything works great over the Ethernet ports, but does not when linking the two mikrotik switches via the SFP ports. Setup details below. Any insights would be much appreciated!
Setup 1
This works great. The VLAN is accessible on the second CSS326-24G-2S+RM 1GbE.
VLAN1 :
(meraki switch) over 1GbE → (1)CSS326-24G-2S+RM over 1GbE → (2)CSS326-24G-2S+RM over 1GbE
RSTP state on (1)CSS326-24G-2S+RM
Role: designated
Type: point-to-point
RSTP state on (2)CSS326-24G-2S+RM
Role: root
Type: point-to-point
Setup 2
This setup does not work. VLAN 1 is not accessible on the second CSS326-24G-2S+RM 1GbE.
VLAN1 :
(meraki switch) 1GbE → (1)CSS326-24G-2S+RM over SFP → (2)CSS326-24G-2S+RM over SFP
RSTP state on (1)CSS326-24G-2S+RM
Role: designated
Type: edge
RSTP state on (2)CSS326-24G-2S+RM
Role: designated
Type: edge
What “Default VLAN ID” have you set for ethernet and SFP interfaces and what is the RSTP State in the second setup?
Have you tried to disable RSTP on these ports?
I have not changed any of the default settings on either of the CSS326-24G-2S+RM.
Default VLAN ID is 1 for every port on both switches. I tried disabling RSTP on each
switch and then both, no success.
Don’t use the edge-port type for 802.1q trunking to another switch. Also you might try MSTP as it can sometimes solve STP interop issues with other switches.
Setup 1
This works great. The VLAN is accessible on the second CSS326-24G-2S+RM 1GbE.
VLAN1 :
(meraki switch) over 1GbE → (1)CSS326-24G-2S+RM over 1GbE → (2)CSS326-24G-2S+RM over 1GbE
RSTP state on (1)CSS326-24G-2S+RM
Role: designated
Type: point-to-point
RSTP state on (2)CSS326-24G-2S+RM
Role: root
Type: point-to-point
Setup 2
This setup does not work. VLAN 1 is not accessible on the second CSS326-24G-2S+RM 1GbE.
VLAN1 :
(meraki switch) 1GbE → (1)CSS326-24G-2S+RM over SFP → (2)CSS326-24G-2S+RM over SFP
RSTP state on (1)CSS326-24G-2S+RM
Role: designated Type: edge
RSTP state on (2)CSS326-24G-2S+RM
Role: designated
In RouterOS it is possible to specify which bridge ports are edge ports. > Edge ports are ports that are not supposed to receive any BPDUs> , this is beneficial since this allows STP to skip the learning and the listening state and directly go to forwarding state. This feature is sometimes called PortFast· You can leave this parameter to the default value, which is auto, but you can also manually specify it, you can set a port as edge port manually for ports that should not have any more bridges behind it, usually these are access ports.
Edge ports are supposed to be for end systems and not other switches.
Use this command to set both bridges to be non-edge - which is the desired state for switch to switch trunking