A while back i stumbled on a set of KB’s for testing UDP heartbeat connectivity between ESXi and vCenter. I wrote this article to describe how to do it.
Now today I had to do the same and went back to these KB’s to find the script. This was however on newer 6.5 U2 hosts and not old 5.5 hosts. And as KB1029919 describes it is only applicable to 4.0.x to 5.5.x versions of ESXi.
Why is this important? Because between ESXi 5.5.x and 6.5 U2 the included Python was updated from 2 to 3. Some of you may know that there are many breaking changes in Python 3 when compared to Python 2 and some of those were present in the original udp_client.py script.
So I took the time to fix the few issues that the script had and upload a version to GitHub here. In the Python folder there is a version of udp_client.py that is Python 3 compatible and I included the original script as udp_client-v2.py for reference.
The major changes were in line 25 that print is now a function and has to be used with parentheses and the “%” change to “,” as seen here:
original: print "\nSent %s UDP packets over port %s to %s" % (numtimes,port,host) python 3: print("\nSent %s UDP packets over port %s to %s", (numtimes, port, host))
After syntax error was fixed I found that there was a change to how “socket.sendto” works and it now expects a bytearray instead of a string. Simple fix was to introduce a int variable “datasize” set to 100 and change the “data” variable from “100” to “bytearray(datasize)” as seen here:
original: data = "100" python 3: datasize = 100 data = bytearray(datasize)
After this the scipt works on a 6.5 U2 host and I was able to UDP connectivity.
This also marks the first time I have my own public Github repsitory so – yay! 🙂