WALinuxAgent: HTTP GET errors after upgrade to 2.2.18

After an upgrade of WALinuxAgent to 2.2.18, we are starting to see many errors such as INFO [HTTP Retry] Attempt 2 of 3: [HTTP Failed] HTTP GET IOError timed out.

Relevant lines from the logfile for waagent:

2017/10/02 17:42:40.184193 INFO Agent WALinuxAgent-2.2.17 discovered WALinuxAgent-2.2.18 as an update and will exit
2017/10/02 17:42:40.254095 INFO Determined Agent WALinuxAgent-2.2.18 to be the latest agent
2017/10/02 17:42:40.478907 INFO Agent WALinuxAgent-2.2.18 is running as the goal state agent
2017/10/02 17:42:40.490486 INFO Wire server endpoint:168.63.129.16
2017/10/02 17:42:40.501360 INFO Start env monitor service.
2017/10/02 17:42:40.499748 INFO Event: name=WALinuxAgent, op=HeartBeat, message=, duration=0
2017/10/02 17:42:40.515109 INFO Configure routes
2017/10/02 17:42:40.522481 INFO Gateway:None
2017/10/02 17:42:40.526873 INFO Routes:None
2017/10/02 17:42:40.536965 INFO WALinuxAgent-2.2.18 running as process 51976
2017/10/02 17:42:40.544028 INFO Wire server endpoint:168.63.129.16
2017/10/02 17:42:40.550571 INFO Event: name=WALinuxAgent, op=AutoUpdate, message=, duration=0
2017/10/02 17:42:40.562539 INFO Wire server endpoint:168.63.129.16
2017/10/02 17:42:40.598330 INFO Wire server endpoint:168.63.129.16
2017/10/02 17:42:40.631295 INFO [Microsoft.Azure.Extensions.LinuxAsm-2.2.4] Target handler state: enabled
2017/10/02 17:42:40.641515 INFO [Microsoft.Azure.Extensions.LinuxAsm-2.2.4] [Enable] current handler state is: enabled
2017/10/02 17:42:40.651968 INFO [Microsoft.Azure.Extensions.LinuxAsm-2.2.4] Update settings file: 7.settings
2017/10/02 17:42:40.662079 INFO [Microsoft.Azure.Extensions.LinuxAsm-2.2.4] Enable extension [asm-extension enable]
2017/10/02 17:42:41.675332 INFO Event: name=Microsoft.Azure.Extensions.LinuxAsm, op=Enable, message=Launch command succeeded: asm-extension enable, duration=0
2017/10/02 17:42:41.713076 INFO [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9025] Target handler state: enabled
2017/10/02 17:42:41.724272 INFO [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9025] [Enable] current handler state is: enabled
2017/10/02 17:42:41.735678 INFO [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9025] Update settings file: 2.settings
2017/10/02 17:42:41.746546 INFO [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9025] Enable extension [diagnostic.py -enable]
2017/10/02 17:42:41 LinuxAzureDiagnostic started to handle.
2017/10/02 17:42:41 [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9027] cwd is /var/lib/waagent/Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9027
2017/10/02 17:42:41 [Microsoft.OSTCExtensions.LinuxDiagnostic-2.3.9027] Change log file to /var/log/azure/Microsoft.OSTCExtensions.LinuxDiagnostic/2.3.9027/extension.log
2017/10/02 17:42:42.760388 INFO Event: name=Microsoft.OSTCExtensions.LinuxDiagnostic, op=Enable, message=Launch command succeeded: diagnostic.py -enable, duration=0
2017/10/02 17:42:42.811160 INFO Event: name=WALinuxAgent, op=ProcessGoalState, message=, duration=2212
2017/10/02 17:57:41.007228 INFO Agent WALinuxAgent-2.2.18 launched with command 'python3 -u bin/WALinuxAgent-2.2.18-py2.7.egg -run-exthandlers' is successfully running
2017/10/02 17:57:41.022163 INFO Event: name=WALinuxAgent, op=Enable, message=Agent WALinuxAgent-2.2.18 launched with command 'python3 -u bin/WALinuxAgent-2.2.18-py2.7.egg -run-exthandlers' is successfully running, duration=0
2017/10/06 08:48:12.130059 INFO [HTTP Retry] Attempt 2 of 3: [HTTP Failed] HTTP GET IOError timed out
2017/10/06 08:48:27.150650 INFO [HTTP Retry] Attempt 3 of 3: [HTTP Failed] HTTP GET IOError timed out
2017/10/06 08:48:42.170697 WARNING Exception retrieving extension handlers: [000008] [Wireserver Exception] [000009] [HTTP Failed] HTTP GET IOError timed out
2017/10/06 08:48:42.189159 ERROR Event: name=WALinuxAgent, op=, message=Exception retrieving extension handlers: [000008] [Wireserver Exception] [000009] [HTTP Failed] HTTP GET IOError timed out, duration=0

Azure OS: Ubuntu 14.04.5 LTS, Ubuntu 16.04.3 LTS WALinuxAgent version: 2.2.18 Python: 2.7.12