On ACI how do we check and confirm DHCP is not managed by Switch ?

[Network_Sarovani]

Hi Team , 

How do we check for a given subnet DHCP is on the switch or on the server or on the 3rd party IPAM ?

Thank you .

[Robert Burns]

DHCP (other than the Infra subnet) isn't managed by ACI.  ACI simply relays DHCP offers if configured to do so.   If you're asking if a subnet is currently defined on ACI as a Bridge Domain (BD) that's another question.  Please clarify.

Robert

[Network_Sarovani]

Yes , BD configured on ACI for these BD subnets ..Will there be ny configuration related to DHCP in ACI ?

[Robert Burns]

The only 'DHCP" specific config that relates to ACI would be if you needed to implement DHCP relay for your hosts to relay their DHCP requests to a dhcp server/IPAM in a different subnet/EPG.  There's plenty of guides online detailing how to setup dhcp relay on ACI.  If your dhcp server/IPAM is connected to the same EPG as the clients, there's no additional configure required as they'll have L2 connectivity between client & server.

If you want to see which BD subnets are configured across the entire fabric, the quickest method is to poll the API or use CLI.  From any APIC you can use:

moquery -c fvSubnet | egrep "ip|dn"

This will show you all the Subnets configured on Bridge Domains.

Robert

[Network_Sarovani]

Will this command work on the leaf switch ?

[Robert Burns]

No, its a fabric wide command.  If you want something specific to the leaf, just use "show ip int brief".

Robert

[ashishr]

Hi @Network_Sarovani

To check DHCP relay on leaf switch you can use the following CLI-

show dhcp internal info relay address interface [leaf:interfaceVlan#]

You can find more CLI here-

https://community.cisco.com/legacyfs/online/attachments/document/technote-aci-dhcprelay_external-v7.pdf

Thanks,

AR