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.
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 performs the following functions:
- General information about Switch
- Switch management
- Configuration reset
- Backup and restore configuration
- Firmware upgrade
|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.|
|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|
Link Tab allows you to:
- Configure Ethernet ports
- Monitor status of Ethernet ports
|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)|
|Crossover||Detect crossover cable (Read-only)|
|Flow control||Enable or disable flow control|
Forwarding Tab provides advanced forwarding options among switch ports, port locking, port mirroring, bandwidth limit and broadcast storm control features.
|Forwarding||Forwarding table - allows or restricts traffic flow between specific ports|
|Broadcast Storm Control||
Provides detailed information about received and transmitted packets.
VLAN configuration for Switch ports.
VLAN mode for ingress port:
|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
|Force VLAN ID||Whether to apply
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 ID||VLAN ID of the packet|
|Ports||Ports the packet should be mapped to|
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.
|MAC||MAC address (Read-only)|
|Ports||Ports the packet should be forwarded to (Read-only)|
Static Hosts Tab
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.
|Ports||Ports the packet should be forwarded to|
|Drop||Packet can be cloned and sent to mirror-target port|
|Mirror||Packet with certain MAC address coming from certain ports can be dropped|
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 matchers. SwOS allow you to implement limited number of access control list rules (32 simple rules (either L2 or L3 matchers are used) or 16 complex rules (both L2 and L3 matchers are used)).
Each rule contains a matching part and an action part.
Matching part parameters
|From||Match port that packet came in from|
|MAC Src||Match by source MAC address and mask|
|MAC Dst||Match by destination MAC address and mask|
|Ethertype||Match by protocol encapsulated in the payload of an Ethernet Frame|
Match by VLAN header presence:
|VLAN ID||Match by VLAN tag ID|
|Priority||Match by priority in VLAN tag|
|IP Src||Match by source IP address and mask|
|IP Dst||Match by destination IP address and mask|
|Protocol||Match by IP protocol|
|DSCP||Match by IP DSCP field|
Action part parameters
|Redirect To||Whether to force new destination ports (If
|Redirect To Ports||Destination ports for|
|Mirror||Clones matching packets and send them 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|
Following example will show to drop ICMP packets destined to Switch itself. It will be impossible to ping Switch on port 5.
SNMP Tab consists of settings to monitor the Switch remotely.
|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 on RB250GS using BOOTP. This example shows how to reinstall SwOS using RouterOS.
- 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.