Learn Editor: Update troubleshoot-resource-bridge.md

Author: alt-key

articles/azure-arc/resource-bridge/troubleshoot-resource-bridge.md

@@ -147,6 +147,20 @@ This occurs when the management machine is trying to reach the ARB VM IP by SSH
 
 If you receive an error that contains `Not able to connect to https://example.url.com`, check with your network administrator to ensure your network allows all of the required firewall and proxy URLs to deploy Arc resource bridge. For more information, see [Azure Arc resource bridge network requirements](network-requirements.md).
 
+### Not able to connect - network and internet connectivity validation failed
+
+When deploying Arc resource bridge, you may receive an error with `errorCode` as `PostOperationsError`, `errorResponse` as code `GuestInternetConnectivityError` with a URL specifying port 53 (DNS). This may be due to the appliance VM IPs being unable to reach DNS servers, so they can't resolve the endpoint specified in the error. 
+
+Error example: 
+
+`{ _errorCode_: _PostOperationsError_, _errorResponse_: _{\n\_message\_: \_{\\n  \\\_code\\\_:\\\_GuestInternetConnectivityError\\\_,\\n\\\_message\\\_:\\\_Not able to connect to http://aszhcitest01.company.org:55000. Error returned: action failed after 5 attempts: Get \\\\\\\_http://aszhcitest01.company.org:55000\\\\\\\_: dial tcp: lookup aszhcitest01.company.org on 127.0.0.53:53: read udp 127.0.0.1:32975-\\u003e127.0.0.53:53: i/o timeout. Arc Resource Bridge network and internet connectivity validation failed: cloud-agent-connectivity-test. 1.  check your networking setup and ensure the URLs mentioned in : https://aka.ms/AAla73m are reachable from the Appliance VM.   2. Check firewall/proxy settings\\\_\\n }\_\n}_ }`
+
+Error example: 
+
+`{ _errorCode_: _PostOperationsError_, _errorResponse_: _{\n\_message\_: \_{\\n  \\\_code\\\_: \\\_GuestInternetConnectivityError\\\_,\\n  \\\_message\\\_: \\\_Not able to connect to https://linuxgeneva-microsoft.azurecr.io. Error returned: action failed after 5 attempts: Get \\\\\\\_https://linuxgeneva-microsoft.azurecr.io\\\\\\\_: dial tcp: lookup linuxgeneva-microsoft.azurecr.io on 127.0.0.53:53: server misbehaving. Arc Resource Bridge network and internet connectivity validation failed: http-connectivity-test-arc. 1. Please check your networking setup and ensure the URLs mentioned in : https://aka.ms/AAla73m are reachable from the Appliance VM.   2. Check firewall/proxy settings\\\_\\n }\_\n}_ }`
+
+To resolve the error, work with your network administrator to allow the appliance VM IPs to reach the DNS servers. For more information, see [Azure Arc resource bridge network requirements](network-requirements.md).
+
 ### Http2 server sent GOAWAY
 
 When trying to deploy Arc resource bridge, you might receive an error message similar to:
@@ -263,16 +277,6 @@ To check if the DNS server is able to resolve an address, from a machine where w
 
 ```Resolve-DnsName -Name "http://aszhcitest01.company.org:55000" -Server "<dns-server.com>"```
 
-### Not able to connect - i/o timeout
-
-When deploying Arc resource bridge, you may receive an error with `errorCode` as `PostOperationsError`, `errorResponse` as code `GuestInternetConnectivityError` with keywords `i/o timeout` and `read udp`. This may be due to the appliance VM IPs being unable to reach DNS servers, so they can't resolve the MOC cloud agent address endpoint specified in the error. 
-
-Error example: 
-
-```{ _errorCode_: _PostOperationsError_, _errorResponse_: _{\n\_message\_: \_{\\n  \\\_code\\\_:\\\_GuestInternetConnectivityError\\\_,\\n\\\_message\\\_:\\\_Not able to connect to http://aszhcitest01.company.org:55000. Error returned: action failed after 5 attempts: Get \\\\\\\_http://aszhcitest01.company.org:55000\\\\\\\_: dial tcp: lookup aszhcitest01.company.org on 127.0.0.53:53: read udp 127.0.0.1:32975-\\u003e127.0.0.53:53: i/o timeout. Arc Resource Bridge network and internet connectivity validation failed: cloud-agent-connectivity-test. 1.  check your networking setup and ensure the URLs mentioned in : https://aka.ms/AAla73m are reachable from the Appliance VM.   2. Check firewall/proxy settings\\\_\\n }\_\n}_ }```
-
-To resolve the error, work with your network administrator to allow the appliance VM IPs to reach the DNS servers.
-
 ### Authentication handshake failure
 
 When running an `az arcappliance` command, you might see a connection error: `authentication handshake failed: x509: certificate signed by unknown authority`