SwOS/CRS317

Summary

SwOS is an operating system designed specifically for administration of MikroTik switch products.

SwOS is configurable from your web browser. It gives you all the basic functionality for a managed switch, plus more: allows to manage port-to-port forwarding, broadcast storm control, apply MAC filter, configure VLANs, mirror traffic, apply bandwidth limitation and even adjust some MAC and IP header fields.

Warning: Each RouterBoard switch series device has its own firmware which cannot be installed on other series models! CRS317-1G-16S+ supports SwOS v2.3 and newer.

Connecting to the Switch

Open your web browser and enter IP address of your Switch (192.168.88.1 by default) and login screen will appear.

Alt text — CRS317-1G-16S+ with loaded SwOS (CSS317-1G-16S+)

SwOS default IP address: 192.168.88.1, user name: admin and there is no password.

Note: MikroTik Neighbor Discovery protocol tools can be used to discover IP address of Mikrotik switch. Manual:IP/Neighbor_discovery

Interface Overview

CRS317-1G-16S+ SwOS interface menu consists of multiple tabs: Link, SFP, SFP Status, Port Isolation, LAG, Forwarding, Stats, Errors, Histogram, VLAN, VLANs, Static Hosts, Hosts, SNMP, ACL, System and Upgrade.

Description of buttons in SwOS configuration tool:

Append - add new item to the end of the list
Apply All - applies current configuration changes
Cut - removes item from the list
Clear - resets properties of the item
Discard Changes - removes unsaved configuration
Insert - add new item to the list (places it before current item)
Sort - sort VLAN table by VLAN-IDs; sort host table by MAC addresses

Change Password - changes password of the switch
Logout - logout from current Switch
Reboot - reboot the switch
Reset Configuration - reset configuration back to factory defaults
Choose File - browse for upgrade or backup file
Upgrade - upgrade firmware of the Switch
Restore Backup - restore Switch using selected backup file
Save Backup - generate and download backup file from the Switch

System

System Tab performs the following functions:

General information about Switch
Switch management
Configuration reset
Backup and restore configuration

Note: SwOS uses a simple algorithm to ensure TCP/IP communication - it just replies to the same IP and MAC address packet came from. This way there is no need for Default Gateway on the device itself.

Property	Description
IP Address	IP address of the switch
Identity	Name of the switch (for Mikrotik Neighbor Discovery protocol)
Allow From	IP address from which the switch is accessible. Default value is '0.0.0.0/0' - any address
Allow From Ports	List of switch ports from which it is accessible
Allow From VLAN	VLAN ID from which the switch is accessible (VLAN Mode on ingress port must be other than `disabled` in order to connect)
Watchdog	Enable or disable system Watchdog. It will reset CPU of the switch in case of fault condition
Independent VLAN Lookup	Enable or disable independent VLAN lookup in the Host table for packet forwarding
Mikrotik Discovery Protocol	Enable or disable Mikrotik Neighbor Discovery protocol
MAC Address	MAC address of the switch (Read-only)
Serial Number	Serial number of the switch (Read-only)
Board Name	MikroTik model name of the switch (Read-only)
Uptime	Current switch uptime (Read-only)

Health and Global RSTP

Property	Description
Temperature	Shows PCB temperature in celsius temperature scale (Read-only)

Property	Description
Bridge Priority (hex)	RSTP bridge priority for Root Bridge selection
Port Cost Mode	There are two methods for automatically detecting RSTP port cost depending on link speed. `short`: 10G - 2; 1G - 4; 100M - 10; 10M - 100 `long`: 10G - 2000; 1G - 20000; 100M - 200000; 10M - 2000000
Root Bridge	The priority and MAC address of the selected Root Bridge in the network (Read-only)

Password and Backup

Link

Link Tab allows you to:

Configure Ethernet and SFP+ ports
Monitor link status of Ethernet and SFP+ ports

Note: CRS317-1G-16S+ supports up to 10232 byte Jumbo frames when running SwOS.

Property	Description
Enabled	Enable or disable port
Name	Editable port name
Link Status	Current link status (Read-only)
Auto Negotiation	Enable or disable auto negotiation
Speed	Specify speed setting of the port (requires auto negotiation to be disabled)
Full Duplex	Specify duplex mode of the port (requires auto negotiation to be disabled)
Flow control	Enable or disable 802.3x Flow control

SFP and SFP Status

SFP and SFP Status Tabs allow you to monitor status of SFP modules.

Port Isolation

Port Isolation table allows or restricts traffic forwarding between specific ports.

Note: It is possible to check/uncheck multiple checkboxes by checking one of them and then dragging horizontally (Click & Drag)

LAG

CRS317-1G-16S+ supports 802.3ad (LACP) compatible link aggregation as well as static link aggregation to ensure failover and load balancing based on Layer2 and Layer3 hashing.

Up to 16 link aggregation groups with up to 8 ports per a group are supported.

Each individual port can be configured as an passive, active or static LACP using the control protocol.

Property	Description
Mode (default: passive)	Specify LACP packet exchange mode between ports: `Passive`: Place port in listening state, use LACP only when it's countrary port uses active LACP mode `Active`: Prefer to start LACP regardless countrary port mode `Static`: Place port in LACP mode=on

Property	Description
Group	Create static LACP group
Trunk (read only)	Represents group number port belongs to.
Partner (read only)	Represents partner mac-address.

Forwarding

Forwarding Tab provides advanced forwarding options among switch ports, port locking, port mirroring, bandwidth limit and broadcast storm control features.

Property	Description
Port Lock	`Port Lock` - Enable or disable MAC address learning on this port `Lock On First` - Enable or disable MAC address learning on this port (MAC address from the first received packet will still be learnt)
Port Mirroring	`Mirror Ingress` - Whether traffic entering this port must be copied and forwarded to mirroring target port `Mirror Egress` - Whether traffic leaving this port must be copied and forwarded to mirroring target port `Mirror To` - Mirroring target port
Broadcast Storm Control	`Storm Rate (%)` - Limit the number of broadcast packets transmitted by an interface. The rate is measured in percents of the link speed. `Include Unknown Unicast` - Include unicast packets without an entry in host table in `Storm Rate` limitation
Bandwidth Limit	`Ingress Rate` - Limit traffic entering this port (bps)

RSTP

Per port RSTP configuration and monitoring is available in the RSTP menu.

Stats, Errors and Histogram

These menus provide detailed information about received and transmitted packets.

VLAN and VLANs

Port VLAN settings

Property	Description
`VLAN Mode` (disabled \| optional \| enabled; Default: optional)	VLAN filtering mode, these options are relevant to egress ports. `disabled` - VLAN table is not used. Switch discards packets with a VLAN tag on egress ports. If packet has a VLAN tag and the VLAN ID matches `Default VLAN ID` on egress ports, then with `VLAN Receive=any` the switch will remove the VLAN tag and forward the packet. `optional` - Handle packets with VLAN tag ID that is not present in VLAN table just like packets without VLAN tag, disabled VLAN filtering `enabled` - Drop packets with VLAN tag ID that is not present in VLAN table. Default VLAN ID must be specified for access ports since it will be used to tag traffic from a certain port, enabled VLAN filtering
`VLAN Receive` (any \| only tagged \| only untagged; Default: optional)	Ingress traffic filtering based on VLAN tag presence. `any` - Allows tagged and untagged packets on a certain port `only tagged` - Allows only packets with a VLAN tag `only untagged` - Allows only packets without a VLAN tag
`Default VLAN ID` (integer: 1..4095; Default: 1)	VLAN ID which will be assigned on ingress traffic. Only has effect on untagged traffic, for tagged traffic this parameter will be ignored. All traffic (tagged and untagged) will be tagged with this VLAN ID if `Force VLAN ID` is used. Can be used to untag egress traffic, if used with `VLAN Mode=disabled` when this parameter matches the packet's VLAN ID.
`Force VLAN ID` (integer: yes \| no; Default: no)	Assigns the `Default VLAN ID` value to all ingress traffic (tagged and untagged). Has effect in all VLAN Modes. If port receives tagged traffic and `Default VLAN ID` is set to 1, then with this parameter the egress traffic will be untagged.

VLAN table settings

Property	Description
`VLAN ID` (integer: 1..4095; Default: 0)	VLAN ID to which assign ports.
`Port Isolation` (yes \| no; Default: yes)	Use settings from `Port Isolation` menu to isolate the defined VLAN to only certain ports. When disabled, the switch will ignore port isolation configuration and forward traffic with the defined VLAN ID only to ports that are checked as members.
`Learning` (yes \| no; Default: yes)	Enables or disables MAC address learning on the defined VLAN. If disabled, then all learned MAC addresses will appear as they have had been learned from VLAN 1.
`Mirror` (yes \| no; Default: no)	Enables or disables VLAN based mirroring. When enabled and `Mirror To` is set in the `Forwarding` menu, then all traffic from the defined VLAN will be mirrored to the selected port.
`IGMP Snooping` (yes \| no; Default: no)	Enables or disables IGMP Snooping on the defined VLAN. When enabled, the switch will listen to IGMP Join and Leave requests from the defined VLAN and only forward traffic to ports, which have sent IGMP membership requests from the defined VLAN. When disabled, the switch will flood all VLAN member ports with Multicast traffic.
`Members` (ports; Default: none)	Group of ports, which are allowed to forward traffic on the defined VLAN.

VLAN configuration for switch ports.

VLAN membership configuration for switch ports.

Static Hosts

Static host table entries. Static entries will take over dynamic if dynamic entry with same mac-address already exists. Also by adding a static entry you get access to some more functionality.

Hosts

This table represents dynamically learnt MAC address to port mapping entries. When Switch receives a packet from certain port, it adds the packets source MAC address and port it received the packet from to host table, so when a packet comes in with certain destination MAC address it knows to which port it should forward the packet. If the destination MAC address is not present in host table then it forwards the packet to all ports in the group. Dynamic entries take about 5 minutes to time out. CRS317-1G-16S+ supports 16383 host table entries.

IGMP Snooping

IGMP Snooping which controls multicast streams and prevents multicast flooding is implemented in SwOS starting from version 2.5. The feature allows a switch to listen in the IGMP conversation between hosts and routers.

Enable option under System tab.

Available IGMP snooping data:

Group Adress
VLAN
Member Ports

Possibility to enable IGMP Snooping for specific VLAN ID.

SNMP Tab

SwOS supports SNMP v1 and uses IF-MIB, SNMPv2-MIB and BRIDGE-MIB for SNMP reporting.

Available SNMP data:

System information
System uptime
Port status
Interface statistics
Host table information

Property	Description
Enabled	Enable or disable SNMP service
Community	SNMP community name
Contact Info	Contact information for the NMS
Location	Location information for the NMS

ACL Tab

An access control list (ACL) rule table is very powerful tool allowing wire speed packet filtering, forwarding and VLAN tagging based on L2,L3 protocol header field conditions.

Each rule contains a conditions part and an action part.

Conditions part parameters

Property	Description
From	Port that packet came in from
MAC Src	Source MAC address and mask
MAC Dst	Destination MAC address and mask
Ethertype	Protocol encapsulated in the payload of an Ethernet Frame
VLAN	VLAN header presence: any present not present
VLAN ID	VLAN tag ID
Priority	Priority in VLAN tag
IP Src (IP/netmask:port)	Source IPv4 address, netmask and L4 port number
IP Dst (IP/netmask:port)	Destination IPv4 address, netmask and L4 port number
Protocol	IP protocol
DSCP	IP DSCP field

Action part parameters

Property	Description
Redirect To	Force new packets destination port
Mirror	Clones packet and sends it to mirror-target port
Rate	Limits bandwidth (bps)
Drop	Drop packet
Set VLAN ID	Changes the VLAN tag ID, if VLAN tag is present
Priority	Changes the VLAN tag priority bits, if VLAN tag is present

Dual Boot

“Dual Boot” feature allows you to choose which operating system you prefer to use, RouterOS or SwOS. Dual Boot manual

Reset and Reinstall

CRS317-1G-16S+ has built-in backup SwOS firmware which can be loaded in case standard firmware breaks or upgrade fails:

Holding Reset button for few seconds while CRS317-1G-16S+ is booting resets configuration and loads backup firmware SwOS 2.3p.
After loading backup firmware SwOS 2.3p it is possible to connect to 192.168.88.1 using web browser and install new SwOS firmware.

SwOS/CRS317

Contents

Summary

Connecting to the Switch

Interface Overview