SDA HOST POOLS and DHCP Process

[Oscar Gomez]

Hello everybody!!!

When I start the onboarding process, Endpoint used the Host pool for established communication with the fabric. The question is about DHCP, you may configure in the host pool if I understand well and the IP obtained from the DHCP is replaced for the IP obtained from Host Pool?

Best regards,

[Mike.Cifelli]

When you configure IP Pools you create global pools, and then reserve an IP pool from a created global pool. This reserved pool then gets assigned/associated to a VN in host onboarding along with the unique SGT (that is already added to the respective VN under Policy section) that will be used for microsegmentation. From there you can take the unique vlan name identifier string that you use in your ISE authz profiles to ensure hosts are properly onboarded during auth. Note if this is wrong you will encounter anycast gateway issues, which obviously will result in dhcp and onboarding issues. During the reserved IP Pool creation (Design->Network Settings->IP Address Pools) you assign the DHCP server that will be used. Your DHCP server should be outside the fabric, and gets configured in DNAC here: Design->Network Settings->Network->DHCP Server. Once configured, you can provision ENs to consume the DHCP configuration. HTH!

[Oscar Gomez]

Thank you, if I understand you , can  I assign the host pools with DHCP Server or manually (Design->Network Settings->IP Address Pools?

[Oscar Gomez]

Thank you, if I understand you , can I assign the host pools with DHCP Server or manually (Design->Network Settings->IP Address Pools?

[Mike.Cifelli · Accepted solution]

Thank you, if I understand you , can I assign the host pools with DHCP Server or manually (Design->Network Settings->IP Address Pools?

-You will need to create the scopes in the DHCP server.  You also must manually reserve IP Pools in DNAC, and associate them with a VN.  During the association phase you will see the unique vlan name identifier I mentioned earlier.  This unique string is used in authz profiles as a radius attribute which is crucial to proper host onboarding.

Note: If you use PnP at all you will need to configure option 43.  See: https://www.cisco.com/c/en/us/td/docs/cloud-systems-management/network-automation-and-management/dna-center/1-3/user_guide/b_cisco_dna_center_ug_1_3/b_cisco_dna_center_ug_1_3_chapter_01011.html

Higher level breakdown:

-Add your DHCP server to be referenced and used in your fabric:  Design->Network Settings->Network->DHCP Server.  When you provision your NADs they will consume network setting configs that get configured here. 

-Create your global ip pool, reserve/create new reserved pool from global pool, during creation add the DHCP Server that will be used for the respective pool:

Note: Generic Pool Type – Wired and wireless endpoint attachment to SD-Access fabric, and fabric enabled wireless AP attachment to SD-Access fabric

-That reserved IP Pool then gets assigned to a VN in host onboarding.

HTH!