Configure>>Switch Settings is where you can configure global switch settings such as the management VLAN, spanning tree for the switch stack, quality of service, and port mirroring. 

 

 

 

Management VLAN

By default, the switch will try to contact Meraki Dashboard on the untagged (native) VLAN. Alternately, you can specify the management VLAN under Configure >> Switch settings. This allows the switch to reach the internet via a trunk port. All switches in a network must use the same management VLAN.


If you change the management VLAN and the switch can no longer obtain a DHCP lease or reach Meraki Dashboard, the switch will revert to its previous management VLAN configuration.


If your network does not allow the native VLAN or any of the default VLANs to DHCP or connect to the internet, you will need to manually assign a management VLAN. To do this, place the switch on a network running DHCP, then from dashboard navigate to Monitor >> Switches and select the target switch. From the details page, choose "Set IP Address" and save your changes.

 

 

Rapid Spanning Tree Protocol (STP/RSTP)

RSTP/STP helps prevent network loops by creating a loop-free network topology. It is important to note that Rapid Spanning Tree (RSTP) is enabled on all ports by default.


RSTP/STP can also be used to create redundant links between switches. Note that when enabled, only one link is active at a time.

Enabling RSTP

As stated, RSTP is enabled by default. In order to toggle RSTP/STP for your entire virtual stack, simply navigate to Configure >> Switch Settings and toggle the "enable" or "disable" RSTP. 

Note: By default, MS series switches are shipped with RSTP/STP disabled. Once connected to dashboard, RSTP will become active if the setting is left at default (enabled).

 

Setting the STP Root Bridge

STP bridge priority will determine which switch is the STP root in the network. The switch with the lowest priority will become the root (MAC address is the tie-breaker) which is the default. If you would like to manually specify which of your switches is your Root, you can do so by navigating to Configure >> Switch Settings and entering a new root bridge rule. 


Note: Changing the STP bridge priority may cause a short disruption on all switches in the network while the spanning tree is re-calculated.

 Note: Please note that STP Portfast (immediate forwarding state) is enabled by default on all ports configured as Access ports.

Quality of Service (QoS)

Please see the section on QoS

For additional details about how the MS handles QoS, see the Knowledge Base

 

 

Port Mirroring

It may be necessary to configure a mirrored port or range of ports. This is often useful for network devices that require monitoring of network traffic, such as a VoIP recording solution or an IDS (Intrusion Detection System).

MS switches support one-to-one or many-to-one mirror sessions. 

 

Configuration

In order to enable and configure a mirrored port or range of ports, navigate to Configure >> Switch Settings. In the "Port Mirroring" section, choose "Add port mirroring on a switch" and specify the Switch, as well as the port you would like to mirror. Now, specify the Mirrored port or ports, using a hyphen ( - ) or comma ( , ) as the delimiting character.

 

In the above example, the "VOIP Mirror" switch is configured to mirror packets on ports 1-8 to port 22. Also, ports 1-2 are configured to mirror to port 47 on the "CORE1" switch.

 

Note: Traffic sent or received over the mirrored ports will also be sent over the mirror port. This allows special monitoring devices to analyze the traffic. Port mirroring is per switch since traffic cannot be mirrored across switches.


MTU Configuration

The Meraki MS Series supports jumbo frames up to 9600 bytes. You can set an MTU size for the entire network (9600 bytes by default) of switches as well as change the MTU settings for individual switches. The network default will apply to all switches that don't have an individual value set, including any new switches added.

 

If you would like to disable support for Jumbo Frames and use Ethernet defaults you can do so by configuring an MTU size of 1500 bytes