{"id":355,"date":"2014-06-29T08:16:01","date_gmt":"2014-06-29T12:16:01","guid":{"rendered":"http:\/\/www.amixa.com\/blog\/?p=355"},"modified":"2014-06-29T08:16:01","modified_gmt":"2014-06-29T12:16:01","slug":"inconsistent-ping-inconsistent-network-connectivity-on-hyper-v-virtual-machine","status":"publish","type":"post","link":"https:\/\/www.amixa.com\/blog\/2014\/06\/29\/inconsistent-ping-inconsistent-network-connectivity-on-hyper-v-virtual-machine\/","title":{"rendered":"Inconsistent ping \/ inconsistent network connectivity on Hyper-V virtual machine"},"content":{"rendered":"<p>I recently came across this issue on one of my virtual server machines, where I just setup a brand new Windows Server W2K12R2 Update 1 virtual machine. It is currently in DHCP status soon to be set as a static IP.<\/p>\n<p>With the client VM machine running (and while multiple other VM&#8217;s are running w\/o any problems), I was experiencing the following:<br \/>\n1) inconsistent ping of the VM<br \/>\n2) inability to remote desktop into the machine (sometimes I could connect, sometimes I would not be able to)<br \/>\n3) DNS resolution issues with that VM<\/p>\n<p>Here is my setup:<br \/>\nWindows Server 2012 R2, Update 1. Hyper-V 6.3.9600.xxxxx<br \/>\nClient: Windows Server 2012, R2, Update 1. Standard Server. Virtual Machine version 5, generation 2.<\/p>\n<p>Network: High quality CAT6\/Gigabit setup.<\/p>\n<p>Here is what it looks like when I do a continuous ping of the virtual machine:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-356\" src=\"http:\/\/www.amixa.com\/blog\/wp-content\/uploads\/2014\/06\/pings.jpg\" alt=\"pings\" width=\"467\" height=\"290\" srcset=\"https:\/\/www.amixa.com\/blog\/wp-content\/uploads\/2014\/06\/pings.jpg 467w, https:\/\/www.amixa.com\/blog\/wp-content\/uploads\/2014\/06\/pings-300x186.jpg 300w\" sizes=\"auto, (max-width: 467px) 100vw, 467px\" \/><\/p>\n<p>After doing a LOT of troubleshooting \/ testing \/ trial &amp; error, here is the fix:<\/p>\n<p>This new VM has a &#8220;DYNAMIC&#8221; MAC address.\u00a0 All the other VM clients on that server have STATIC MAC addresses.<\/p>\n<p>I shut down the VM, adjusted the network settings (under ADVANCED) to a STATIC MAC.<\/p>\n<p>Start the VM.<\/p>\n<p>Login (via remote desktop while sitting on the Hyper-V server itself)<\/p>\n<p><em><strong>Do a continuous ping, and the issue is fixed!<\/strong><\/em><\/p>\n<p>Next, via Remote desktop into the hyper-v server and controlling the machine that way (not remote desktop connecting into the VM itself&#8230;) I switched the machine to a static IP, which was different than the DHCP assigned one.<\/p>\n<p>Reboot machine (for the heck of it)<\/p>\n<p>on my desktop, IPCONFIG \/FLUSHDNS<\/p>\n<p>(at this point depending on how your network is configured you may need to wait a bit for the DNS changes (IP change) to catch up so that your ping works&#8230;)<\/p>\n<p>then try pinging the IP address (not machine name):\u00a0 Works<\/p>\n<p>try pinging the machine name: Works\u00a0 (see above, you may need to wait a bit for your network to catch the DNS changes)<\/p>\n<p>=<\/p>\n<p>The above fix (changing to Static IP) alleviates the need to fiddle with the VM&#8217;s Hardware Acceleration settings, such as VMQ (Virtual Machine Queue) or the Enable IPsec task offloading.\u00a0 On my Hyper-V server both of these are &#8220;CHECKED\/ON&#8221;.<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I recently came across this issue on one of my virtual server machines, where I just setup a brand new Windows Server W2K12R2 Update 1 virtual machine. It is currently in DHCP status soon to be set as a static IP. With the client VM machine running (and while multiple other VM&#8217;s are running w\/o any problems), I was experiencing<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[95,8,94,96],"class_list":["post-355","post","type-post","status-publish","format-standard","hentry","category-windows-server","tag-hyper-v","tag-microsoft-windows-server","tag-network-issues","tag-virtual-machine"],"_links":{"self":[{"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/posts\/355","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/comments?post=355"}],"version-history":[{"count":1,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/posts\/355\/revisions"}],"predecessor-version":[{"id":357,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/posts\/355\/revisions\/357"}],"wp:attachment":[{"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/media?parent=355"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/categories?post=355"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.amixa.com\/blog\/wp-json\/wp\/v2\/tags?post=355"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}