Just when we thought our brand spanking new Meraki is working like a charm, we started getting calls from teachers saying that the Apple TV’s kept on disconnecting every few minutes and in some cases it would disconnect every few seconds, this got really frustrating – as we did not face many issues with our previous Cisco Wireless Setup.
Its been over one month and we still haven’t figured out what is going on, we searched the internet to find help and tried them all, still no luck. If any of you are out there with a similar network setup, please read along to see how you could troubleshoot Apple TV issues
Our Network Infra consist of 2 Cisco cores in VSS mode with multiple VLAN, all Apple TV’s are on a particular VLAN and wired
All our Access points are MR42 & Switches be MS350 (no L3 routing enabled)
Teachers are connected to a Staff SSID (configured in Bridge mode and WPA2)
How did it all unfold?
Initially, when our teachers started complaining, we would restart the AP and ask them to restart their computer, but then this became school-wide and spread like a virus – it kind of made the IT look bad because we just shelled out 1 million for this new Network Infra.I went into the classrooms multiple times to figure out what was going on and started doing a bunch of changes to the network – to the point where I even lost track of what all I did.
What did I do?
Minimum Bitrate: I changed this setting on the Meraki SSID to 36 Mbps – that means no more 802.11b devices, well tough crap for anyone who still has them.This means no more of those old devices would fight for valuable airtime leaving more bandwidth for the rest of the school owned devices; the roaming seemed better too after I changed this setting
Dual-band operation with band steering: this was recommended by some experts in order to increase the utilization of the 5GHZ Band which has much less interference, I thought this would do the trick, my gut was telling me that getting the Apple Macs to use the 5GHZ would be the answer, the 2.4ghz is used largely and has better range, but it also comes with ton of interference from microwaves, neighbouring SSID’s, hotspots etc . but this setting seemed to have caused more harm than good, because now I started noticing that the Mac clients were constantly hopping between the 2.4 and the 5Ghz band where I noticed a pattern where the Mac would get disconnect from the ATV when the client kept switching radios ( not AP’s or SSID )
Manual 5Ghz Band Assignment: Since I couldn’t turn off the 2.4Ghz radio on the SSID because I still had a ton of devices that needed them, I decided to start manually turning off the 2.4Ghz on individual AP’s to try and force the clients to use. Did I have any luck ? not really, the disconnections were still intermittent, some teachers started saying it was better and some started saying it was worse.Felt I was getting back to square one every time.
Now this became a dangerous obsession, and I created a Meraki Support ticket, and they asked me to capture the packets using their packet capture utility, while that feature was not working just when I needed it the most, I decided to sit in the classrooms and started monitoring the behaviour of the clients with regards to the WiFi connectivity.I also read some articles on how the Mac and Apple TV connect via Bonjour and that the apple tv used channel no: 6 on the 2.4Ghz and 149 & 153 on the 5Ghz for their peer to peer communication.
Now I started to find patterns on client’s that were connected to the SSID on channel 6,149 & 153 were dropping their ATV connections more frequently.
Manual Channel assignment: After I had read the above two articles, I started manually changing the channel to anything other than 14
Channel width: The channel width on the 5GHz band was set to 40MHz, upon Meraki support engineers recommendations I set it to 20 MHz which means the wireless AC clients could not utilize the full glory of the AC network, but at this point we needed stability, plus in dense AP environment it is highly recommended to reduce the Channel width, the channel width could be set to 40 or 80 MHz in an auditorium or outdoor AP when the Access Point density is less.
Did this all work out in the end?
A combination of the tinkering with the channel width, manually disabling the 2.4 GHz band and manual assignment of channels on the 5 GHz to anything other than channel 149 seems to have alleviated most of the problems, but every now and then there are the intermittent disconnections between the Apple TVs and the clients.I will be updating this post once I have it all completely sorted out.
An update: As of September 2017, I must say things are looking a lot better, an upgrade of the Meraki Switch and Wireless firmware and OSX upgrade to Sierra, the Apple TV connections feels a lot more stable. The Meraki firmware supports Apple 802.1r and Fast Roaming, which could help alleviate some of the roaming issues. I am still yet to try these out BTW.
However, i still have concerns about the Meraki switches and the Cisco Core Switch Network not playing nicely with the Virtual Switching System ( VSS ). I am still doing some research to get to the bottom of this.I will update this blog post as soon I find some more