Cannot Access Internet from within Azure Virtual Machine

I've got a Windows Server 2012 virtual machine running in Azure that prior to system updates that were rolled out last week could connect to Internet addresses such as Yahoo.com without issue. I do not currently have any virtual networks configured for this Azure tenant nor have I modified any of its network settings, so the VM was making the connections with its default network configuration. On August 7, 2014 I rebooted the virtual machine to apply some required system updates to the operating system, and following that reboot the VM could not longer connect to the Internet. I am able to lookup domains in DNS, but cannot ping those domains from the command line or open web sites via a browser.

I've released its IPconfig via the command line and rebooted the server multiple times, both from within a remote desktop connection and from the Azure Management Portal, but these actions have not resolved the issue. I've also tried disabling the Windows Firewall, but even with it fully disabled for all profiles the server cannot access the Internet.

Are there additional configuration steps I need to take to reconnect this VM to Internet sites, or has something changed which requires me to make further changes? Below is the result of running ipconfig /all on the server for the relevant network adapter configured on the server:

Ethernet adapter Ethernet 4:

   Connection-specific DNS Suffix  . : Bruce.e5.internal.cloudapp.net
   Description . . . . . . . . . . . : Microsoft Hyper-V Network Adapter #4
   Physical Address. . . . . . . . . : 00-15-5D-F8-4A-35
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::90b1:ae10:5bdd:8d2xxxx(Preferred)
   IPv4 Address. . . . . . . . . . . : 100.79.110.x(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.254.0
   Lease Obtained. . . . . . . . . . : Monday, August 11, 2014 9:20:03 AM
   Lease Expires . . . . . . . . . . : Saturday, September 19, 2150 4:57:50 AM
   Default Gateway . . . . . . . . . : 100.79.110.1
   DHCP Server . . . . . . . . . . . : 100.78.85.42
   DHCPv6 IAID . . . . . . . . . . . : 352327005
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1B-54-4E-D3-00-15-5D-F8-59-A0
   DNS Servers . . . . . . . . . . . : 100.79.110.120
   NetBIOS over Tcpip. . . . . . . . : Enabled

Thank you,

John

MCITP and MCTS: SharePoint, Virtualization, Project Server 2007
My books on Amazon: The SharePoint 2010 Disaster Recovery Guide andThe SharePoint 2007 Disaster Recovery Guide.
My blog: My Central Admin.