SwOS

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.

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.

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

SwOS interface menu consists of 10 tabs: Link, Forwarding, Statistics, VLAN, VLANs, Static Hosts, Hosts, SNMP, ACL and System.

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 Tab

File:Swos system.png

System Tab performs the following functions:

• General information about Switch
• Switch management
• Configuration reset
• Backup and restore configuration
• Firmware upgrade

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 service is accessible. Default value is '0.0.0.0/0' - any address
Allow From Ports	List of switch ports from which the service is accessible
Allow From VLAN	VLAN ID with which the service is accessible (VLAN Mode on ingress port must be other than disabled in order to connect)
Mikrotik Discovery Protocol	Enable or disable Mikrotik neighbor discovery protocol
Watchdog	Enable or disable system watchdog. It will reset CPU of the switch in case of fault condition
MAC Address	MAC address of the Switch (Read-only)
Version	Firmware version of the Switch
Uptime	Current Switch uptime

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.

Firmware Upgrade

Firmware can be upgraded/downgraded by selecting firmware file and pressing upgrade button. Switch will reboot automatically after successful upgrade.

Note: Manual power cycle is necessary 5 seconds after upgrade button is pressed if you are upgrading from SwOS v1.0

Link Tab

File:Swos link.png

Link Tab allows you to:

• Configure Ethernet ports
• Monitor status of Ethernet ports

Property	Description
Enabled	Enable or disable port
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 to specify)
Full Duplex	Specify duplex mode of the port (requires auto negotiation to be disabled to specify)
Flow control	Enable or disable flow control

Forwarding Tab

File:Swos forwarding.png

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

Property	Description
Forwarding	Forwarding table - allows or restricts traffic flow between specific ports
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 recieved 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
Bandwidth Limit	Ingres Rate - Limit traffic entering this port (bps) (only supported on RB250GS) Egress Rate - Limit traffic leaving this port (bps)
Broadcast Storm Control	Storm Rate - Limit the number of broadcast packets transmitted by an interface Include Unicast - Include unicast packets without an entry in host table in Storm Rate limitation (only supported on RB250GS)

Statistics Tab

File:Swos statistics.png

Provides detailed information about received and transmitted packets.

Packet Flow

Packet processing through RB250GS is described here: Atheros8316 packet flow diagram

VLAN Tab

File:Swos vlan.png

VLAN configuration for Switch ports.

Property	Description
VLAN Mode	VLAN mode for ingress port: disabled - VLAN table is not used. Switch ignores VLAN tag part of tagged packets optional - Handle packets with VLAN tag ID that is not present in VLAN table just like packets without VLAN tag enabled - Drop packets with VLAN tag ID that is not present in VLAN table. Packets without VLAN tag are treat as tagged packets with Default VLAN ID strict - Same as enable, but also checks VLAN support for inbound interface (drop packets with VLAN tag ID and ingress port that are not present in VLAN table)
VLAN Receive	Defines the type of allowed packets on ingress port: any / only tagged / only untagged (only supported on RB260GS)
Default VLAN ID	Switch will treat untagged ingress packets as they are tagged with this VLAN ID. VLAN tag itself will be added only if there is VLAN Header = add if missing specified on egress port
Force VLAN ID	Whether to apply Default VLAN ID to incoming packets with VLAN tag
VLAN Header	leave as is - if VLAN header is present it remains unchanged always strip - if VLAN header is present it is removed from the packet add if missing - if VLAN header is not present it is added to the packet (VLAN ID will be Default VLAN ID of ingress port)

Example

• 802.1Q Trunk
• 802.1Q Trunk with two switches

VLANs Tab

File:Swos vlans.png

VLAN tables specifies certain forwarding rules for packets that have specific 802.1q tag. Basically the table contains entries that map specific VLAN tag IDs to a group of one or more ports. Packets with VLAN tags leave switch through one or more ports that are set in corresponding table entry. VLAN table works together with destination MAC lookup to determine egress ports. VLAN table supports up to 4096 entries.

RB250GS VLANs tab

Property	Description
VLAN ID	VLAN ID of the packet
Ports	Ports the packet should be mapped to

RB260GS VLANs tab

Property	Description
VLAN ID	VLAN ID of the packet
Ports	Each port has individual VLAN header options for each VLAN ID. Depending on VLAN mode if lookup is done in this table, egress action of packets is processed by this option. Egress option from VLAN tab is ignored.

Hosts Tab

File:Swos hosts.png

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 X and port it received the packet from to host table, so when a packet comes in with destination MAC address X 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.

Note: RB250GS supports 2k host table entries.

Property	Description
MAC	MAC address (Read-only)
Ports	Ports the packet should be forwarded to (Read-only)

Static Hosts Tab

File:Swos static hosts.png

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.

Property	Description
MAC	MAC address
Ports	Ports the packet should be forwarded to
Mirror	Packet can be cloned and sent to mirror-target port
Drop	Packet with certain MAC address coming from certain ports can be dropped

ACL Tab

File:Swos acl.png

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. SwOS allow you to implement limited number of access control list rules (32 simple rules (only L2 conditions are used); 16 rules where both L2 and L3 conditions are used; or 8 advanced rules where all L2,L3 and L4 conditions are used).

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 IP address, netmask and L4 port number
IP Dst (IP/netmask:port)	Destination IP address, netmask and L4 port number
Protocol	IP protocol
DSCP	IP DSCP field

Action part parameters

Property	Description
Redirect To	Whether to force new destination ports (If Redirect To is enabled and no ports specified in Redirect To Ports, packet will be dropped )
Redirect To Ports	Destination ports for
Mirror	Clones packet and sends it to mirror-target port
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

SNMP Tab

File:Swos snmp.png

SNMP Tab consists of settings to monitor the Switch remotely.

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

Reinstall SwOS firmware

It is possible to upload and install SwOS firmware using BOOTP. This example shows how to reinstall SwOS using RouterOS.

Note: Each RouterBoard switch model has its own firmware which cannot be installed on other models.

• RB250GS supports SwOS v1.0 and newer.
  
• RB260GS supports SwOS v1.7 and newer.

• Configure IP address and DHCP server with BOOTP enabled on the installation router.

/ip address
add address=192.168.88.254/24 interface=ether1

/ip pool
add name=dhcp_pool1 ranges=192.168.88.1
/ip dhcp-server
add address-pool=dhcp_pool1 bootp-support=dynamic interface=ether1 disabled=no
/ip dhcp-server network
add address=192.168.88.0/24 gateway=192.168.88.254

• Upload new SwOS firmware file to the router filesystem.

[admin@MikroTik] /file> print 
 # NAME             TYPE             SIZE                 CREATION-TIME       
 0 swos-1.2.lzb     .lzb file        38142                sep/02/2010 08:40:17

• Configure TFTP server.

/ip tftp
add allow=yes disabled=no ip-addresses=192.168.88.1 read-only=yes \
    real-filename=swos-1.2.lzb

• Hold the RESET button of the switch when starting it.
• After few seconds ACT LED will start blinking. Wait till ACT LED blinks twice as fast and release RESET button.
• Make ethernet connection between the switch and ethernet port you configured DHCP server on. After few seconds new firmware should be successfully uploaded and installed.