Troubleshooting AP Disconnect Issues

Use this guide to help with troubleshooting issues for APs disconnecting from the cloud without opening a ticket to the support team. To troubleshoot the issue, we need to know the possible cause of this issue. The LED on the Mist AP can be very helpful if the AP ever has a problem connecting to the cloud. It will blink out error codes to explain exactly what the problem is. Please see this page https://www.mist.com/documentation/what-is-led-telling-me/ for more details.

Below are some of the common issues for AP disconnects and steps to help you resolve them:

AP LED is not blinking at all

Explanation: The AP is not powering up at all and no LED blinks in the AP is most likely related to power issues from the switch.

Steps to Troubleshoot:

  1. Check whether the MAC address of the AP is being learned on the switch port where the AP is connected.
  2. Check the power logs from the APs to see if PoE is being enabled on the switch port or if the switch is providing power to the AP.
  3. Try changing the cable and the switch port to see if the AP is powering up or not.
  4. If you have any other working AP at the same site, try swapping this AP with the working one to check if your AP works on the other port. (If your APs are already installed and this is not possible, please skip this step)
  5. If none of the above steps work, you can open a support ticket for our support team for additional troubleshooting (if required).

AP LED is blinking green/yellow

Explanation: The green/yellow LED pattern on the AP indicates that the AP is connecting to the cloud. Whenever an AP boots up it tries to connect to the cloud to fetch its configurations.

Steps to Troubleshoot:

  1. Our APs need some specific ports to be opened on the firewall to get connected to the cloud. Please go through this page: https://www.mist.com/documentation/ports-enable-firewall/ to see which ports need to be enabled.
  2. If all the ports mentioned in the above URL are enabled and the AP is still blinking green/yellow, connect a laptop on the same switch port and try to go to the URL: http://ep-terminator.mistsys.net/about in the browser to check if that resolves the host. You should get an output that looks something like:
    {
    "version": "0.3.4476",
    "git-commit": "0db544d97d09c21dd2ea0778c1f6d03465861c9d",
    "build-time": "2020-03-16_23:45:06_UTC",
    "go-runtime": "go1.14",
    "env": "production",
    "procname": "ep-terminator/🌧/provider=aws/env=production/host=ep-terminator-172-31-16-17-762f638f-production.mistsys.net/pid=12226/user=terminator",
    "start-time": "2020-03-19T01:32:54Z",
    "uptime": 707675.367648
    }
  3. If you are not able to get the details, check the firewall logs to see if there is any policy that might be blocking this AP from reaching the ep-terminator.mistsys.net URL.
  4. If you are still not able to figure out firewall logs, please reach out to our support team and we will assist you in fixing the issue.

AP LED is blinking yellow 2 times

Explanation: 2 yellow blinking lights on the LED means there is some layer 2 issues on the switch or the AP.

Steps to Troubleshoot:

  1. Do a cable test to check if the cable through which the AP is connected is good and working.
  2. Check whether the MAC address of the AP is being learned on the switch port where the AP is connected.
  3. Check the eth0 errors on the switch port if there are any.
  4. Try changing the cable and the switch port and see if the AP is powering up or not.
  5. If you have any working AP at the same site, try swapping this AP with the working one to check if the AP connects on the other port. (If your APs are already installed and this is not possible, please skip this step)
  6. If you are still not able to resolve the issue, please open a support ticket to our support team for additional troubleshooting.

AP LED is blinking yellow 3 times

Explanation: 3 yellow blinking lights on the LED means the AP is not able to fetch an IP from the DHCP/static configuration. There are two ways to assign an IP to the AP, either through DHCP or through the Static configurations. You can configure any AP manually on the Access Points page. Please note that if the AP is booting up for the first time, the IP configuration must be set to DHCP. Once the AP gets an IP from DHCP and is connected to the cloud, you can then configure the static configuration on the AP.

Steps to Troubleshoot (in the case of DHCP):

  1. Check the switch port configuration to see whether or not the correct configurations (such as Native VLAN and VLAN ID) have been made.
  2. Check the logs on the DHCP server to see if the leases are available in the DHCP pool.
  3. Connect a laptop on the switch port where the AP is connected and check if your laptop is able to get an IP from the VLAN management pool of APs.
  4. If your laptop is not able to get an IP, then you need to check with your DHCP team to fix the DHCP pool. Doing a port mirror on the switch port can help identify which step in the DORA process is failing.
  5. If your laptop is able to get an IP on the same port but the AP is not able to get the IP, open a support ticket with us for further troubleshooting.

Steps to Troubleshoot (in the case of Static configuration):

  1. It is assumed here that this is not a new AP and that it was connected to the cloud earlier. Check the static configurations set on the Mist portal. If the configurations on the AP are not correct, the AP will get stuck when trying to connect to the cloud.
  2. Power down the AP by shutting down the PoE on switch port where AP is connected or remove the physical cable from the AP which is providing power.
  3. Put the correct configurations on the switch port.
  4. Reset the AP to the factory default settings. Please look at this page for the process to factory reset the AP: https://www.mist.com/documentation/factory-reset-ap/
  5. Now, power the AP back up for it to connect to the cloud again.
  6. If all configurations look good and the AP is still not able to get an IP, please feel free to reach out to Mist Support for more assistance.

AP LED is blinking yellow 4 times

Explanation: 4 yellow blinking lights on the LED means there is no default gateway found in the DHCP lease or static configuration.

Steps to Troubleshoot:

  1. Check the DHCP pool configuration to see whether or not the default gateway is being actually set in the pool.
  2. If there is a static configuration set on the AP, check if the default gateway is configured properly. if it is not configured properly, follow steps 2 through 5 mentioned in AP LED is blinking yellow 3 times: Steps to Troubleshoot (in the case of Static configuration).
  3. Do a port mirroring for the switch port and get packet capture. In the DHCP offer packet from the Server, check if there is any IP in the default gateway field.
  4. If there is no default gateway found in DHCP offer, reach out to your DHCP server team to fix the configuration on DHCP server.
  5. If the AP is still blinking the same pattern after configuring the DHCP properly, reach out to Mist support for more troubleshooting.

AP LED is blinking yellow 5 times

Explanation: 5 yellow blinking lights on the LED means there was a default gateway IP found but the AP was not able to reach out to the default gateway.

Steps to Troubleshoot:

  1. Verify all the configurations on the switch port (VLAN, Native VLAN) as well as the DHCP pool configuration to see if the correct IP is being set on it.
  2. If there is a static configuration set on the AP, check if the default gateway is configured properly. if it is not configured properly, follow steps 2 through 5 mentioned in AP LED is blinking yellow 3 times: Steps to Troubleshoot (in the case of Static configuration).
  3. If the configuration is all correct but the AP is still showing 5 blinking yellow LEDs, connect a laptop on the same VLAN/network or if possible, on the same switch port where the AP is connected and try to ping the default gateway. You can get the default gateway information by running ipconfig /all in the terminal.
  4. If ping fails, reach out to your network admin to check issues on the wired side. If it succeeds and the AP still fails on that port, reach out to Mist support for more troubleshooting.

AP LED is blinking yellow 6 times

Explanation: 6 yellow blinking lights on the LED means there is no DNS server IP found in the DHCP lease or static configuration.

Steps to Troubleshoot:

The steps are pretty much the same as those explained above in AP LED is blinking yellow 4 times. But here, instead of looking for the default gateway configuration, we need to check the DNS server configuration.

AP LED is blinking yellow 7 times

Explanation: 7 yellow blinking lights on the LED means there is no DNS response to DNS lookup. It received DNS server via DHCP but cannot reach or ping the Mist cloud. Once the AP gets an IP from the DHCP, the AP tries to reach ep-terminator.mistsys.net for its connectivity. If the DNS server is not able to resolve reach this URL, the AP will not be able to connect to the cloud and will blink yellow 7 times.

Steps to Troubleshoot:

  1. Connect a laptop on the same VLAN/network and try to resolve the URL ep-terminator.mistsys.net into an IP by doing a nslookup from your terminal. For example:
    C:\Users\RavinashR>nslookup ep-terminator.mistsys.net
    Server: dns.google
    Address: 8.8.8.8
    Non-authoritative answer:
    Name: ep-term-production-1584483204-1989267174.us-west-1.elb.amazonaws.com
    Addresses: 52.9.76.55
    13.57.102.113
    Aliases: ep-terminator.mistsys.net
  2. If your laptop is not able to resolve this URL, you can explicitly add this URL in your DNS server.
  3. If the issue doesn’t get fixed after adding this URL, you can check the firewall/proxy logs to check if the traffic for this URL is getting dropped in the network. You can also take a packet capture for more analysis.
  4. If after following all the steps above, you are not able to fix this issue, you can reach out to Mist Support for further assistance.

AP LED is blinking yellow 1+N times

Explanation: For all cases where the AP is blinking yellow from 1+2 to 1+9 times, the problem is coming from the cloud side and we request that you open a case for our Support team to troubleshoot in these cases.

Please Note before you open a support ticket:

Whenever you open a ticket to our support team for AP disconnect issues, we sincerely request that you provide the below details for us so that we can quickly help you resolve your issue.

  • The exact LED patterns on the AP, if possible 1-minute video
  • Are you getting the mac-address of the AP on your switch port?
  • Is the AP getting power from the switch?
  • Is the AP getting IP and is it pinging on the L3 gateway of your network?
  • Which troubleshooting steps have been followed for fixing the issue?
  • Please provide all the additional logs which can help us get to the root cause of the issue.