Category Archives: Microsoft

Microsoft Failover Cluster node not sending out Gratuitous ARP requests after a failover

This was a particularly odd issue which I had never experienced before so I thought it’s worth blogging about it.

During a normal MS Failover Cluster failover operation, the node calming the cluster roles sends out a GARP request to notify the networking infrastructure of the MAC address change. The Layer 3 switch / router then updates the MAC address in the ARP table and packets are routed to the node which claimed the cluster roles.  Recently I found myself troubleshooting a MS Failover cluster deployment which wasn’t behaving quite in this manner.

Some background info:

  • For the sake of this blog post lets call the 2 nodes A and B.
  • The nodes are running Server 2016, SQL 2012 and Microsoft Failover Cluster services.
  • Each node has 2 NICs, one for the client and management network, and one for the heartbeat network.
  • The cluster consists of 3 Network resource; a cluster IP address and 2 SQL instance addresses which float between the 2 nodes depending on which one is active.
  • All 3 IP addresses are in the same VLAN.
  • Running continues ping to all 3 IP addresses during failover tests.

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Customising the Cisco Jabber MSI file using Microsoft Orca

Last year we moved on to a Cisco based telephony infrastructure and installed Cisco Jabber on our client machines. We deployed Cisco Jabber via Microsoft group policies using the standard MSI file provided by Cisco. The deployment was successful however we ended up getting a lot of complaints from the users about not being able to login.

After some troubleshooting together with support, we established that the GPO deployed Jabber application was trying to authenticate against a WebEx Connect server on the cloud rather than the Unified Communication server based locally in the LAN. Since there was no WebEx Messenger subscription, the login process was failing. The solution was to customise the MSI file and prevent the installed Jabber application from trying to authenticate against a Webex Connect server.

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