I have a lab network setup at my house with similar equipment to our office that I use for testing different features and functionality. Since I have had this installed (~ 2 years) I've had an intermittent but recurring problem with connectivity to various wireless devices that I have never been able to fully resolve.
I have a 5508 Wireless controller with a handful of 3502i APs spread throughout my house. The controller is connected to a 3560X switch. And I have an ASA 5510 firewall as my Firewall/Internet Gateway.
When I work from home I most often work from a desktop computer in my office and have a Windows RDP session to a laptop located in another room in my house on one of my monitors as a working space (I know this is weird but there is a good reason). This laptop is connected via WiFi at all times.
Occasionally, I will lose connectivity to this laptop (or not be able to connect back to my desktop from it) and have to start an extended ping from the laptop to the desktop to re-establish connectivity. A while ago I performed some deeper analysis on what was happening and what I found is that when the connectivity breaks the problem is that the desktop is unable to resolve the MAC address of the laptop. It sends out ARP requests but never receives any reply back.
Why would the controller stop replying to ARP requests for the IP address of the laptop?
If I log into the controller while this is happening it shows the laptop as a connected client, and has its IP address and MAC address listed fine in the clients section. In order to avoid getting up every time I need to reconnect, I normally hop to a system I control across one of my VPN tunnels via RDP, then connect BACK to the laptop and start the ping to re-establish connectivity back to my main desktop machine. This works because the firewalls ARP cache hasn't cleared yet. And then everything works fine again... unless I manually clear my ARP cache. Sometimes clearing the ARP cache will result in the exact same problem again and I will lose connection. Other times it seems to repopulate almost immediately and the connection doesn't drop.
A wireshark debug from the desktop reveals that ARP requests simply go out with no reply, confirming what is happening.
As a note, I have set both the User Idle Timeout and the ARP timeout to 24 hours to try and help but this has not had any effect.
This problem seems to go away and then come back. In fact, I havent been experiencing this issue for probably a couple months recently and then it just started again in the last few days which is why I am back to posting here. No changes to the network were made in the meantime that could account for this change in behavior. I am currently running version 7.2.111.3 but this behavior has persisted through at least four software upgrades so I don't think it's an issue with a specific version but I don't really know.
I occasionally epxerience connectivity issues in my house to other devices as well that I use less often like a printer, network camera, apple tv so I now feel like these issues are likely all related.
Does anyone have any advice for things I could try next in the troubleshooting process to pinpoint what is breaking?
