最後更新: 2020-01-24

介紹

Hardware

CRS125-24G-1S-RM (layer 3 Smart Switch)

• HK$1600
• 25個千兆交換口  (1xSFP和 24xRJ45)
• LCD Display
• CPU: 600MHz X 1
• RAM: 128M
• Architecture: MIPS-BE
• Mirco USB Port: X 1
• PCB Temperature Monitor: Yes

CRS326-24G-2S+    

• Switch Chip: Marvell-98DX3236
• CPU: 800MHz X 1

Ingress & Egress

Ingress - packets going Into the switch

Egress - packets Exiting the switch

SW Chip 硬解

In previous versions (prior to RouterOS v6.41) you had to use the master-port property to switch multiple ports together

Setting a port as type "None" makes it a switch chip master port,
and you may then set all the other ports to this port as a master port.
In this configuration, all ports communicate through the switch chip.

In RouterOS v6.41 this property is replaced with the bridge hardware offloading feature

Use the hw parameter to select which bridge will use hardware offloading.
(built-in switch chip to forward packets)

In most cases the packet will not be visible to RouterOS (only statistics will show that a packet has passed through),
this is because the packet was already processed by the switch chip and never reached the CPU

Passing the packet to the CPU port will give you the opportunity to route packets to different networks,
perform traffic control and other software related packet processing actions.

* Currently(ROS v6.41)) it is possible to create only one bridge with hardware offloading on CRS3xx series devices.

# show port

/interface print

# status

/interface print stats

Rx is received from the view of that interface.

Tx is transmitted from the view of that interface.

Bandwidth Limiting

Both Ingress Port policer and Shaper provide bandwidth limiting features for CRS switches.

# Ingress Port Policer sets RX limit on port:

i.e.

/interface ethernet switch ingress-port-policer
add port=ether5 meter-unit=bit rate=10M

port: 要填 interface 的 NAME, 如果有空格, 那就要用 "

meter-unit: (bit | packet; Default: bit)

meter-len (layer-1 | layer-2 | layer-3; Default: layer-1)

• layer-1 - includes entire layer-2 frame + FCS + inter-packet gap + preamble.
• layer-2 - includes layer-2 frame + FCS.
• layer-3 - includes only layer-3 + ethernet padding without layer-2 header and FCS.

packet-types (packet-types; Default: all types from description)

burst=N / Nk / Nm (# Default: 100k)

i.e.

/interface ethernet switch ingress-port-policer
add meter-unit=packet port="ether5" rate=3k burst=5k

# Shaper sets TX limit on port:

/interface ethernet switch shaper
add port=ether5 meter-unit=bit rate=10M

e.g.

/interface ethernet switch shaper
add meter-unit=packet port="ether5" rate=4k burst=5k

Traffic Storm Control

The same Ingress Port policer also can be used for the traffic storm control

to prevent disruptions on Layer 2 ports caused by broadcast, multicast or unicast traffic storms.

# Broadcast storm control example on ether5 port with 500 packet limit per second:

/interface ethernet switch ingress-port-policer
add port=ether5 rate=500 meter-unit=packet packet-types=broadcast

其他

• ros_sw_chipset
• ros_vlan