Manual:CRS3xx series switches
Applies to RouterOS: v6.41 +
Summary
The Cloud Router Switch series are highly integrated switches with high performance ARM CPU and feature-rich packet processor. The CRS switches can be designed into various Ethernet applications including unmanaged switch, Layer 2 managed switch, carrier switch and wired unified packet processing.
Warning: This article applies to CRS3xx series switches and not to CRS1xx/CRS2xx series switches.
Features
| Features | Description |
|---|---|
| Forwarding |
|
| Mirroring |
|
| VLAN |
|
Models
This table clarifies main differences between Cloud Router Switch models.
| Model | Switch Chip | CPU | Wireless | SFP+ port | Access Control List | Jumbo Frame (Bytes) |
| CRS326-24G-2S+ | Marvell-98DX3236 | 800MHz | - | + | + | 10218 |
| CRS317-1G-16S+ | Marvell-98DX8216 | 800MHz | - | + | + | 10218 |
Abbreviations
- FDB - Forwarding Database
- MDB - Multicast Database
Port Switching
Since v6.40rc29 bridges will handle all Layer2 forwarding and the use of switch chip (hw-offload) will automatically turn on if appropriate conditions are met.
The rest of RouterOS Switch features remain untouched in usual menus.
By default all newly created bridge ports have hw=yes option and it allows enabling of hw-offload when possible. If such functionality is not required, it can be disabled by hw=no on bridge port to have completely software operated bridging.
Note: Downgrading to previous RouterOS versions will not restore master-port configuration. The bridge with no hw-offload will appear instead and master-port configuration will have to be redone from the beginning.
Example
Use the command lines below to create a bridge and add ports to it. On CRS3xx using other bridge protocol modes will also enable hardware offloading.
/interface bridge add name=bridge1 igmp-snooping=no protocol-mode=none /interface bridge port add bridge=bridge1 interface=ether2 add bridge=bridge1 interface=ether3 add bridge=bridge1 interface=ether4 add bridge=bridge1 interface=ether5
Make sure that hardware offloading is enabled. If H flag is available next to the desired interface, then hardware offloading is active on that port. If hardware offloading flag is not shown, then make sure you haven't enabled features that disable hardware offloading.
[admin@MikroTik] > /interface bridge port print Flags: X - disabled, I - inactive, D - dynamic, H - hw-offload # INTERFACE BRIDGE HW PVID PRIORITY PATH-COST INTERNAL-PATH-COST HORIZON 0 H ether2 bridge1 yes 1 0x80 10 10 none 1 H ether3 bridge1 yes 1 0x80 10 10 none 2 H ether4 bridge1 yes 1 0x80 10 10 none 3 H ether5 bridge1 yes 1 0x80 10 10 none
Note: On CRS3xx series switches bridge STP/RSTP/MSTP, IGMP Snooping and VLAN filtering settings don't affect hardware offloading, bonding on the other hand disables hardware offloading
Host Table
Sub-menu: /interface bridge host
| Property | Description |
|---|---|
| age (read-only: time) | The time since the last packet was received from the host |
| bridge (read-only: name) | The bridge the entry belongs to |
| external-fdb (read-only: flag) | Whether the host was learned using wireless registration table |
| local (read-only: flag) | Whether the host entry is of the bridge itself (that way all local interfaces are shown) |
| mac-address (read-only: MAC address) | Host's MAC address |
| on-interface (read-only: name) | Which of the bridged interfaces the host is connected to |
Example
- Use this command to get the active host table:
[admin@MikroTik] > /interface bridge host print Flags: L - local, E - external-fdb BRIDGE MAC-ADDRESS ON-INTERFACE AGE bridge1 00:00:00:00:00:01 ether2 3s bridge1 00:01:29:FF:1D:CC ether2 0s L bridge1 00:0C:42:52:2E:CF ether2 0s bridge1 00:0C:42:52:2E:D0 ether2 3s bridge1 00:0C:42:5C:A5:AE ether2 0s
VLAN
Bridge VLAN Filtering since RouterOS v6.40rc29 provides VLAN aware Layer2 forwarding and VLAN tag modifications within the bridge. This set of features makes bridge operation more like a traditional Ethernet switch and allows to overcome Spanning Tree compatibilty issues compared to configuration when tunnel-like VLAN interfaces are bridged. Bridge VLAN Filtering configuration is highly recommended to comply with STP (802.1D), RSTP (802.1w) standards and is mandatory to enable MSTP (802.1s) support in RouterOS.
The main VLAN setting is vlan-filtering which globally controls vlan-awareness and VLAN tag processing in the bridge. If vlan-filtering=no, bridge ignores VLAN tags, works in a shared-VLAN-learning (SVL) mode and cannot modify VLAN tags of packets. Turning on vlan-filtering enables all bridge VLAN related functionality and independent-VLAN-learning (IVL) mode. Besides joining the ports for Layer2 forwarding, bridge itself is also an interface therefore it has Port VLAN ID (pvid).
| Property | Description |
|---|---|
| vlan-filtering (yes | no; Default:no) | Globally enables or disables VLAN functionality for bridge. |
| pvid (1..4094; Default:1) | Port VLAN ID (pvid) specifies which VLAN the untagged ingress traffic is assigned to. It applies e.g. to frames sent from bridge IP and destined to a bridge port. |
STP/RSTP/MSTP
TODO
IGMP Snooping
IGMP Snooping which controls multicast streams and prevents multicast flooding is implemented in RouterOS starting from version 6.41. It's settings are placed in bridge menu and it works independently in every bridge interface. Software driven implementation works on all devices with RouterOS but CRS1xx/2xx/3xx series switches also support IGMP Snooping with hardware offloading.
- Use this command to enable IGMP Snooping on a bridge interface:
/interface bridge set bridge1 igmp-snooping=yes
- Use this command to get current Multicast Database entries:
[admin@MikroTik] > /interface bridge mdb print
BRIDGE VID GROUP PORTS
bridge1 200 229.1.1.2 ether3
ether2
ether1
bridge1 300 231.1.3.3 ether4
ether3
ether2
bridge1 400 229.10.10.4 ether4
ether3
bridge1 500 234.5.1.5 ether5
ether1
Global Switch Settings
TODO
Port Settings
TODO
Switch Rules (ACL)
TODO
See also
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