Using Chromecast in your Cisco enterprise WLAN environment

Chromecast is an interesting product even for businesses, especially it’s screen casting function (although still listed as experimental) can be utilized to present your PC to an external monitor – reducing the need for the right cables or adapters in between.

In an enterprise environment, however, it can prove difficult to connect a device like the Chromecast to WiFi networks that require features like dot1x authentication. This was the case in my company and searching for answers led me to a deployment guide from Cisco, the vendor we use our wireless solution. Although relevant it did not completely solve my issue, so if you are struggling with the same problem just keep on reading.

The deployment guide from Cisco focuses heavily on multicast, both within a single network and between wireless networks. In my case connecting the Chromecast to the same network as the company users was not possible, but the answer was far simpler than the suggested solution from Cisco. In the end it is all a question of mDNS (multicast DNS) being properly set up to announce your Chromecast’s service.

First, according to Cisco’s guide, enable global multicast:

Controller -> Multicast -> Enable Global Multicast mode

Global multicast

From here on, the rest is easily set up as follows:

Controller -> mDNS -> General -> Enable mDNS Global Snooping

mDNS global

Controller -> mDNS -> General -> Add new service to Master Services Database (_googlecast._tcp.local)

mDNS services

Controller -> mDNS -> Profiles -> Edit Default-mdns-profile and add service to list

mDNS profiles

Next we need to create a separat WLAN for the Chromecast devices:

WLANs -> Select Create New and click GO

On the General tab

  • Name your Chromecast  device WiFi
  • Set Radio Policy to b/g band only (a not supported by ChromeCast)
  • Select the same back-end Interface as the client WLAN is using

WLAN chromecast general

On the Security tab

  • ChromeCast needs WPA2-PSK. MAC filtering is optional security 

WLAN chromecast security #1

WLAN chromecast security #2

WLAN chromecast security #3

On the Advanced tab

  • Make sure P2P communications are not blocked

WLAN advanced

  • Enable mDNS snooping and use the previously defined policy

WLAN advanced #2

If you opted in on MAC filtering security for your WLAN:

Security -> AAA -> MAC Filtering -> Select New 

  • Enter MAC address of the ChromeCast (this is displayed when using the ChromeCast setup tool).
  • Select WLAN Profile Name that was previously made for these devices
  • Add a fitting Description 
  • Select the same back-end Interface name as the WLAN is using

WLAN security

Now you are ready to go. Just connect your Chromecast to your monitor and use your Chromecast PC or mobile app to set up the connection. If you are setting up MAC filtering security on your device WLAN you can find the MAC address of your Chromecast on the bottom of your “select Wi-Fi” part of the setup.

 

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9 thoughts on “Using Chromecast in your Cisco enterprise WLAN environment

  1. Hi Rune,

    I am using mDNS for AppleTV/Airplay without using Multicast globally enabled on the WLC 5508 as indicated by Cisco documentation and it is working fine.

    Do you know if it is MANDATORY to enable globally Multicast on the WLC 5508 to make it work on Chromecast?.

    When I enabled Multicast on the WLC, I could mirror into the Chromecast with no issues and doing MAB with an Cisco ISE as External Radius Server without a local entry on the MAC Filtering Table of the WLC. I could mirror from IPAD, Win 7 and Samsung Galaxy Tab 10.1.

    I was wondering if we can make it work similar to the AppleTV without the Multicast Option enabled globally in the WLC 5508.

    On the other hand, I can only mirror when I have the Chromecast device and the IPAD/Win 7 on the same SSID/Subnet. It is not working when they are on different SSIDs. I thought the mDNS would solve that issue. I am still checking if this problem has something to do with the FW in the middle blocking 1900 UDP.

    thanks in advance for your comments and suggestions.

    AC

    • Hi Abraham,
      I would like to know how the chromecast working in corporate wifi network. Iam facing issues in my office wifi network it not able to show the chromecast device in my android mobile both in the same wifi network.

      • Hi Mathew,

        I have a 1st generation chromecast. It works fine on android based devices and win 7 when I downloaded and installed the corresponding app from here: https://www.google.com/chromecast/setup/

        I am running multicast-unicast on my 5508 Cisco WLC by now and mDNS so I could cast from Subnet A: Samsung Tablet/Chromebook into Chromecast connected to a projector on Subnet B. (NO MULTICAST GLOBALLY ENABLED ON WLC or IGMP)

        The problem that I have now is that IPAD does not work and the Google Home App indicated in the connection setup can discover the Chromecast, reboot remotely the device, display the backdrop but NO CAST unless I install from itunes.apple.com the app = https://itunes.apple.com/ca/app/video-tv-cast-for-chromecast/id907405413?mt=8

        Native Chrome browser on IPAD, Youtube apps, etc; does not work for casting on Chromecast. I am still investigating why.

        Hoping this helps.

  2. Hi Abraham.
    I am by no means a Cisco expert, so bear that in mind when reading this. Enabling global Multicast is in my mind more about enabling the Multicast feature itself. The WLC can be configured to do multicast in either “multicast” or “unicast” (several streams) between the controller and the AP’s. Therefore I think it is necessary to enable this “feature”.
    One of the key points to having both AppleTV and ChromeCast working is the way I see it all about multicast DNS (mDNS). In my blog I explain how to enable this and add a service for ChromeCast. The service entry for AppleTV seems to be there by default (_airplay._tcp.local) and would imply that this should work out of the box. However, like you say yourself, there is quite a difference between having both the “mirrored device” and the AppleTV/ChromeCast on the same WLAN or on separate ones. If, like me, you have to separate these then the answer is to create two WLAN’s but use the same back-end interface towards the cabled infrastructure. This way, mDNS will pick up the AppleTV/ChromeCast announcements and advertise it to the devices connected to the devices connecting through the other WLAN connected on the same subnet or “broadcast domain” so to speak. This way there will be no firewall between the two WLAN’s, traffic will only flow though the WLC.
    Regarding the MAC filtering this was only mentioned as an option to control what devices can connect to the WLAN – MAB will work just as well (I use MAB on our LAN for registering Lync Phone Devices which cannot do dot1x).

    I don’t know if this was helpful at all, but I hope you will sort it out anyhow!

    Best regards,
    Rune

  3. Summary:

    Parts
    Chromecast version 2
    WLC Firmware 7.6

    AP Model CAP3602I-A-K9

    Global Settings:
    AP Multicast Mode enabled on controller
    Enable Global Multicast Mode
    Enable IGMP Snooping
    mDNS Global Snooping
    _googlecast._tcp.local. added as service.
    service is added to default-mdns-profile

    SSID: Users   802.1x auth

    SSID: Devices  WPA2-PSK
    Both SSID on same Interface (same VLAN)
    P2P Blocking Action on both SSID: Disabled
    Aironet IE on both SSID: Disabled
    mDNS Snooping: Enabled
    mDNS Profile: default-mdns-profile

    Results:
    Chromecast appears under _googlecast._tcp.local. mDNS service
    239.255.255.250 appears under monitor->multicast
    Chromecast unable to be detected when user is on Users SSID and chromecast on Devices SSID
    Chromecast is detected when I am on Devices SSID along with chromecast device

    I followed these directions as well:
    http://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/7-6/chromecastDG76/ChromecastDG76.html

    I am at wits end, any idea?

    • Try running AP multicast mode as Unicast instead. I experienced the same as you (only able to connect within same WLAN SSID) when following the same Cisco Chromecast directions.
      The way I see it multicast has little to do with the video streaming and is probably more related to the mDNS (multicast DNS) where the ChromeCast announces it’s presence on the network. This should therefore not put too much extra load on the WLAN traffic. But you might be using other multicast services where this is not an option to you, so be advised.
      AP multicast mode with multicast option may require some additional multicast setup on the upstream network to work properly, I don’t know – but doing it the Unicast way works for me.

  4. Rune,

    You have no idea of how this article helped me. I was facing exactly the same issue, and so far, i wasn’t able to run Chromecast in my Cisco Wireless Network. With this steps, i did work perfectly.

    Thank you very much.

    Gustavo (from Brazil).

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