scan-list and frequency settings

RouterOS General
1

I’ve a general question about the wireless interface parameters scan-list and frequency.

My problem is that I do not fully understand how frequency and scan-list are related to
each other (and are they related at all?) and how exactly the scan-list parameter operates.

Is scan-list only relevant for interfaces in station mode or also for access-point interfaces?
I’d assume that only a station is scanning frequencies to find an AP, so why would an AP
interface utilize a scan-list? Or is an AP also scanning frequencies?

And then you have an explicit frequency=xxx setting on the wireless interface, for both station
mode and AP mode. I assume if I set AP and station frequency values to the same values, what
use would scanning as given by the scan list have in addition to that?

How does the setting of the frequency parameter relate to the scan-list parameter? Do AP mode
interfaces only use frequency value and ignore scan-list and station mode interfaces ignore
frequency and scan as per the specified scan-list ?

If you take a look at the demo.mt.lv router and its wlan1-uplink

[demo@demo.mt.lv] > /interface wireless print
Flags: X - disabled, R - running
 0  R name="wlan1-uplink" mtu=1500 mac-address=00:0C:42:05:03:48 arp=enabled
      disable-running-check=no interface-type=Atheros AR5413 radio-name="000C42050348"
      mode=station ssid="flatant" frequency=4920 band=5ghz scan-list=5600
      rate-set=default supported-rates-b=1Mbps,2Mbps,5.5Mbps,11Mbps
      supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps
      basic-rates-b=1Mbps basic-rates-a/g=6Mbps max-station-count=2007
      ack-timeout=dynamic tx-power=default noise-floor-threshold=default
      periodic-calibration=default burst-time=disabled fast-frames=no dfs-mode=none
      antenna-mode=ant-a wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no
      update-stats-interval=disabled default-authentication=yes default-forwarding=yes
      hide-ssid=no 802.1x-mode=none disconnect-timeout=3s on-fail-retry-time=100ms

you can see that it has a frequency of 4920 and a scan-list of 5600, so these two values have
nothing in common… what can be said about this?

Thanks for clarifications,

–Tom

2

scan list should be set to default-ism. i will check why there is incorrect configuration on demo router. scan list contains standard freuqencies, if for some reason you want to use a frequency that is not on the scan list, add it to the scan list like this:

scan-list=“default-ism,5600” and only then set frequency to 5600

3

normis,

thanks for the information. I assume what you wrote is for routers running as station?

What about the AP side?


–Tom

4

it worn’t hurt to set the same on AP also. although on the ap, the Frequency matters.