Utilizing A Secondary IP On A NIC In A Windows Cluster

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RELEVANT INFORMATION

I have a windows cluster with 3 nodes in it…

  • Node1
  • Node2
  • Node3

I have 4 NICs on each node…

  • NIC1_Host
  • NIC2_Virtuals
  • NIC3_Cluster_HB
  • NIC4_Live_Migration

This is the config for Node2’s NICs…

  • NIC1_Host
    1. IP: 10.71.1.21 – Subnet Mask: 255.255.255.128 – Gateway: 10.71.1.1
    2. IP: 10.71.1.213 – Subnet Mask: 255.255.255.240 – Gateway: N/A
  • NIC2_Virtuals
    1. N/A
  • NIC3_Cluster_HB
    1. IP: 10.71.1.130 – Subnet Mask: 255.255.255.248 – Gateway: N/A
  • NIC4_Live_Migration
    1. IP: 10.71.1.138 – Subnet Mask: 255.255.255.248 – Gateway: N/A

So at this point in my Windows cluster I can see three networks…

  • ClusterHB (10.71.1.130) [Network: 10.71.1.128/29]
  • LAN (10.71.1.21, 10.71.1.213) [Network: 10.71.1.0/25]
  • LiveMigration (10.71.1.138) [Network: 10.71.1.136/29]

Now that all of that is configured I move into my clustered app service that I created called “MyAppService”. Under the general tab I have the list of IP addresses. There are a few things to note here…

  1. I can only have one IP address added to this list.
  2. When I edit or add an IP I can only choose the network 10.71.1.0/25 which is good and bad.

THE QUESTION

So my question is, how can I incorporate my new network in the mix? From what I understand these cluster networks are auto added. But for some reason it’s only adding 1 cluster network per network card and in my case I need it to add 2 for the NIC1_Host NIC. Why is windows clustering not adding a network for the 10.71.1.208/28 network? In the end I expect the following to be shown under the “Networks” section of the cluster…

  • ClusterHB (10.71.1.130) [Network: 10.71.1.128/29]
  • LAN (10.71.1.21) [Network: 10.71.1.0/25]
  • iSCSI (10.71.1.213) [Network: 10.71.1.208/28]
  • LiveMigration (10.71.1.138) [Network: 10.71.1.136/29]

Answer

The use of multiple ips on a single network card can usually only work when they are a clustered resource with the failover cluster manager. In each nic you add a single network ip address with or without a gateway in the operating system. You can add a cluster resource of type ip address to setup a access point for the resource. I use this for things like a sql server instance has an ip address in addition to the client access point so it can be backed up as a virtual point on a network for backup when the resource moves between the cluster hosts. When you go to the create an ip address screen you will only see the logical networks from the network cards as a subnet possible to use.

The Failover Clustering network driver detects networks on the system by their logical subnet. It is not recommended to assign more than one network adapter per subnet, including IPV6 Link local, as only one card would be used by Cluster and the other ignored.

Reference:
Windows Clustering Configuration

Attribution
Source : Link , Question Author : Arvo Bowen , Answer Author : Joel T

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