It's now at ESXi 6.5 Update 1, and you want to get your system up to date. So let's get to it.
Note: Since 6.5.0, VMware have changed the format of their profile bundle name, it now uses a date based format and not a build number.
esxcli network firewall ruleset set -e true -r httpClient esxcli software profile update -p ESXi-6.5.0-20170701001s-standard -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml esxcli software profile update -p ESXi-6.5.0-20170702001-standard -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml esxcli network firewall ruleset set -e false -r httpClient
The first line allows the internal http Client to reach the outside world through the firewall. The second line downloads a patch for the tools-light .VIB (and maybe a few others). Then the updates for the latest ESXi are downloaded and then applied. The last line closes the internal client to the network.
You can monitor the update process through the Web Console by selecting the
/var/log/esxupdate.log file in the Log Viewer, (Host|Monitor|Logs).
Don't forget to
Updated 10 August 2017 to add an additional step to prevent the upgrade failing
Updated 29 July 2017 to reflect ESXi 6.5U1
Updated 20 April 2017 to reflect ESXi 6.5.0d
Updated 14 April 2017 to reflect ESXi 6.5.0c
Created 30 March 2017 with ESXi 6.5.0b