DNAC Cluster VIP address for Cluster link

[M.G.]

Hi team, 

I am trying to configure DNAC MAGLEV Cluster Virtual IP addresses.

DNAC version is 2.1.2 2ndGen, appliance is DN2-HW-APL.

According to the installation guide "By default, Cisco DNA Center configures a link-local subnet (169.254.48.0/20) for this parameter, and we recommend that you use this subnet. "

Therefore, I configured 169.254.48.1/20 for the interface enp94s0f1 and ticked the box "Cluster Link".

The issue is when I get to "MAGLEV CLUSTER DETAILS":

the maglev wizard does not accept 169.254.48.3 as cluster VIP, with the error: Usage of Link Local IP address as Cluster Virtual IP is not allowed".

Question is what should be the cluster VIP so that it is in 169.254.48.0/20 as per guide:

https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/2-1-2/install_guide/2ndGen/b_cisco_dna_center_install_guide_2_1_2_2ndGen/m_plan_deployment_2_1_2_2ndgen.html#concept_t3c_dbj_sfb

Note: in my setup I have mgmt, ent and cluster interfaces. There is no issue with mgmt and ent Cluster VIP addresses.

Thanks.

[PabMar]

Hello,

DNA Center configures a link-local subnet by default on the container subnet. Not the Cluster link.

Hope that helps.

Regards.

[M.G.]

Hi @PabMar 

Thanks for the response.

One paragraph below on the same installation guide says:

Cluster Subnet: Identifies one dedicated IP subnet for the appliance to use in managing and getting IPs for communications among its infrastructure services, such as database access, the message bus, and so on. By default, Cisco DNA Center configures a link-local subnet (169.254.48.0/20) for this parameter, and we recommend that you use this subnet. If you choose to enter another subnet, ensure that it does not conflict with or overlap any other subnet used by Cisco DNA Center's internal network or any external network. Also ensure that the minimum size of the subnet is 21 bits. The subnet you specify must conform with the IETF RFC 1918 and RFC 6598 specifications for private networks, which support the following address ranges:

• 10.0.0.0/8

• 172.16.0.0/12

• 192.168.0.0/16

• 100.64.0.0/10

I just don't know what should be the Cluster link's VIP?

Kind regards.

[PabMar · Accepted solution]

Hi,

Yes, container and cluster subnets are configured in a similar way by default.

Please see step 13 of the same guide in the chapter Configure the Appliance Using the Maglev Wizard.

The Cluster Link subnet, should be a regular subnet, not necessarily routable in your network as this is only for comms between cluster members.

Hope that helps.

Regards.