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	Description
Forwarding	Configurable ports for switching or routing Full non-blocking wirespeed switching Up to 16k MAC entries in Unicast FDB for Layer 2 unicast forwarding Up to 1k MAC entries in Multicast FDB for multicast forwarding Up to 256 MAC entries in Reserved FDB for control and management purposes All Forwarding Databases support IVL and SVL Configurable Port based MAC learning limit Jumbo frame support
Mirroring	Various types of mirroring: Port based mirroring VLAN based mirroring MAC based mirroring 2 independent mirroring analyzer ports
VLAN	Fully compatible with IEEE802.1Q and IEEE802.1ad VLAN 4k active VLANs Flexible VLAN assignment: Port based VLAN VLAN filtering

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	400MHz	-	+	+	10218
CRS317-1G-16S+	Marvell-98DX8216	800MHz	-	+	+	10218

Port Switching

Bridge Hardware Offloading

Since RouterOS v6.40rc29 there are user interface changes which convert RouterBoard master-port configuration into a bridge with hardware offloading. From now on 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.

• Port switching with master-port configuration before v6.40rc29

[admin@MikroTik] > interface ethernet export 
/interface ethernet
set [ find default-name=ether3 ] master-port=ether2
set [ find default-name=ether4 ] master-port=ether2
set [ find default-name=ether5 ] master-port=ether2
[admin@MikroTik] > 

[admin@MikroTik] > interface ethernet print 
Flags: X - disabled, R - running, S - slave 
 #    NAME             MTU MAC-ADDRESS       ARP             MASTER-PORT          SWITCH         
 0 R  ether1          1500 D4:CA:6D:E2:64:64 enabled         none                 switch1        
 1 R  ether2          1500 D4:CA:6D:E2:64:65 enabled         none                 switch1        
 2 RS ether3          1500 D4:CA:6D:E2:64:66 enabled         ether2               switch1        
 3 RS ether4          1500 D4:CA:6D:E2:64:67 enabled         ether2               switch1        
 4 RS ether5          1500 D4:CA:6D:E2:64:68 enabled         ether2               switch1                     
[admin@MikroTik] > 

• Port switching with bridge configuration and enabled hw-offload since v6.40rc29

[admin@MikroTik] > interface bridge export 
/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
[admin@MikroTik] > 

[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
[admin@MikroTik] > 

Following table states what features currently in v6.40rc keep bridge hardware offloading enabled on certain RouterBoard and switch chip models.

Notes:

• Enabling this feature maintains hw-offload: +
• Enabling this feature turns off hw-offload: -

RouterBoard/[Switch Chip] Model	Features in Switch menu	Bridge STP/RSTP	Bridge MSTP	Bridge IGMP Snooping	Bridge VLAN Filtering	Bonding
CRS3xx series	+	+	+	+	+	-
CRS1xx/CRS2xx series	+	+	-	+	-	-
[QCA8337]	+	+	-	-	-	-
[AR8327]	+	+	-	-	-	-
[AR8227]	+	+	-	-	-	-
[AR8316]	+	+	-	-	-	-
[AR7240]	+	+	-	-	-	-
RB750Gr3 [MT7621]	+	-	-	-	-	-
RB1100AHx4 [RTL8367]	+	-	-	-	-	-
[ICPlus175D]	+	-	-	-	-	-

See also

• CRS examples
• CRS features
• Switch Chip Features
• MTU on RouterBOARD

[ Top | Back to Content ]