One of my ESXi 5.1 hosts fails to download patches from vSphere Update Manager (installed together with vCenter 5.1 on a single machine). The relevant part of esxupdate.log reads:
2015-01-15T07:15:08Z esxupdate: esxupdate: ERROR: MetadataDownloadError: ('http://192.168.1.101:9084/vum/repository/hostupdate/BCM/metadata_1362667938.zip', None, "('http://192.168.1.101:9084/vum/repository/hostupdate/BCM/metadata_1362667938.zip', '/tmp/tmpKjrugD', '[Errno 12] Timeout: <urlopen error timed out>')") 2015-01-15T07:15:08Z esxupdate: esxupdate: DEBUG: <<<
From the ESXi I can ping the vCenter IP, but any attempt to establish a TCP connection to port 9084 on the vCenter times out (using
nc -zv 192.168.1.101 9084).
On the vCenter machine (Windows Server 2008 R2) I can verify with netstat, that Update Manager is listening on port 9084 and (using netcat for w32), that a TCP-connection can be established to port 902 on the ESXi.
I checked the firewall settings on both, the ESXi and the vCenter server and both allow TCP on the relevant ports (902 on ESXi and 9084 on vCenter).
Now what confuses me is this: Even on the ESXi hosts that successsfully downloaded updates from the Update Manager via port 9084 a netcat scan on this very port leads to a timeout:
nc: connect to 192.168.1.101 port 9084 (tcp) failed: Connection timed out
I am not sure if I am missing something obvious here. Any ideas, what I could look into to further troubleshoot this issue?