Difference between revisions of "Chromecast across VLANS"

Revision as of 21:24, 5 April 2020

Overview

Chromecast (as well as AirPlay) utilize a discovery protocol to advertise services on a device. This is done through Multicast DNS. mDNS is a link local discovery protocol and therefore doesn't traverse VLANs natively.

Configuring a HP Procurve

Enable mDNS

conf t
mdns enable

Configure the nDNS Gateway

conf t
mdns gateway vlan 100-103,110

Create a mDNS Profile

conf t
mdns profile "Google" rule 1 service "googlecast" action permit
mdns profile "Google" vlan 100-103,110

Enable IGMP Snooping

IGMP Snooping allows the switch limit multicast to only ports that are using it.

conf t
vlan 100-103,110
ip igmp

Verify IGMP

You can check which ports have IGMP traffic by running the following command:

sh ip igmp

or for a specific VLAN

sh ip igmp vlan 110

Testing

1. Place a Google casting device on one of the VLANS listed above (lets say 110), and your mobile phone on another (say VLAN 103). Now try to cast from the YouTube or another Cast capable app. You should see your Google cast devices.

2. No devices listed? Check Verify IGMP. If you don't see any ports listed then mDNS traffic isn't present on your switch.

3. No IGMP Traffic? Check your Access Point configuration and ensure mDNS traffic is permitted. Some AP's and WiFi Routers block or shape mDNS traffic.

4. Still no action? Set the global mDNS action to permit traffic in and out for testing.

conf t
mdns default filter in action permit
mdns default filter out action permit

5. If you see cast devices now, then you may need to change your "Google" mDNS profile from the Create a mDNS Profile section. Its likely the service name is wrong. Service name discovery is beyond the scope of this article. Try googling for 'Chromecast mDNS Service Names'

6. If you do find the correct Service name, remember to disable the 'default filter' rules in step 4.

conf t
mdns default filter in action deny
mdns default filter out action deny

References

https://www.youtube.com/watch?v=gMUnkp6Ao8o

https://community.spiceworks.com/how_to/26481-enable-igmp-on-hp-procurve

https://support.hpe.com/resource3/docDisplay/pdfjs/web/viewer.html?file=%2Fhpesc%2Fpublic%2Fapi%2Fdocument%2Fa00038760en_us%3FdocLocale%3Den_US&locale=en-US&rangeChunkSize=256000&disableAutoFetch=false&disableCache=true&version=20200316053506#_OPENTOPIC_TOC_PROCESSING_d92e33046