{"id":312,"date":"2009-07-09T14:54:49","date_gmt":"2009-07-09T19:54:49","guid":{"rendered":"http:\/\/it.thelibrarie.com\/weblog\/?p=312"},"modified":"2009-07-09T14:54:49","modified_gmt":"2009-07-09T19:54:49","slug":"configure-cisco-to-work-with-windows-nlb","status":"publish","type":"post","link":"https:\/\/it.thelibrarie.com\/weblog\/2009\/07\/configure-cisco-to-work-with-windows-nlb\/","title":{"rendered":"Configure Cisco To Work With Windows NLB"},"content":{"rendered":"<p>Cisco switch, Microsoft Windows Network Load Balancing.<\/p>\n<p>As part of our new site roll-out we&#8217;re using quite a few servers.  Some are running in tandem while others are complete backups just in case.  Basically, for every function we&#8217;re running at least 4 servers (2 load balanced front-facing, 1 backup, and 1 dev\/testing).<\/p>\n<p>Using load balancing is a little more tricky on our environment.<\/p>\n<p>On the test environment, which is strictly a vmware server with a crap-load (technical term) of virtual machines, the Microsoft Load Balancing works without any problems.  Create a virtual IP, point both servers to it, and away you go.<\/p>\n<p>Unfortunately for us this didn&#8217;t work so well on the live production servers.  Why?  The servers required multicast load balancing.  Cisco switches don&#8217;t work well with multicast load balancing.  The router refuses to learn the ARP for the IP address if it&#8217;s coming from a multicast MAC.  I had previously switched the servers to unicast, which solved the problem within the Cisco switches, but then the applications would not function on the servers.<\/p>\n<p>One must create a Static ARP Entry on the gateway switch.<\/p>\n<p>For this exercise I have a switch (192.168.1.245) and a server (192.168.1.173) and a client (192.168.2.202) all of which are Class C \/24 255.255.255.0 addresses.  You will need to know the IP of your server&#8217;s Virtual IP (the one for load balancing) and the MAC address of the virtual IP.  Easy way to find this is to open a cmd window and type the following:<br \/>\n<code>arp -a 192.168.1.173<\/code><br \/>\nOR you can open the network load balance manager and find it listed on the first screen under MAC\/physical address.<\/p>\n<p>Now we need to configure your switch<\/p>\n<blockquote><p>Telnet to your device<br \/>\nType in your password<br \/>\nGo to enable mode<br \/>\n<code>en<\/code><br \/>\nConfiguration terminal<br \/>\n<code>config t<\/code><br \/>\n<code>arp 192.168.1.173 0100.7f5e.ad01<\/code><br \/>\n<code>end<\/code><br \/>\n<code>wr mem<\/code>\n<\/p><\/blockquote>\n<p>Now your pings should work.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Cisco switch, Microsoft Windows Network Load Balancing. As part of our new site roll-out we&#8217;re using quite a few servers. Some are running in tandem while others are complete backups just in case. Basically, for every function we&#8217;re running at least 4 servers (2 load balanced front-facing, 1 backup, and 1 dev\/testing). Using load balancing &hellip; <a href=\"https:\/\/it.thelibrarie.com\/weblog\/2009\/07\/configure-cisco-to-work-with-windows-nlb\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Configure Cisco To Work With Windows NLB<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,4],"tags":[],"class_list":["post-312","post","type-post","status-publish","format-standard","hentry","category-microsoft","category-networking"],"_links":{"self":[{"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/posts\/312","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/comments?post=312"}],"version-history":[{"count":1,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/posts\/312\/revisions"}],"predecessor-version":[{"id":313,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/posts\/312\/revisions\/313"}],"wp:attachment":[{"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/media?parent=312"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/categories?post=312"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/it.thelibrarie.com\/weblog\/wp-json\/wp\/v2\/tags?post=312"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}