topic automatic broadcast domain creation ? in ONTAP Discussions

automatic broadcast domain creation ?

Greg_Wilson — Wed, 04 Jun 2025 10:19:27 GMT

We have 2 new clusters running 9.8P5

Seems when you plug a network cable in it now automatically creates a new broadcast domain for that port.

Default Default 1500 xx-xxxxxx-xxx02-01:e0M complete
Default-1 1500 xx-xxxxxx-xxx02-02:e0M complete
Default-2 1500 xx-xxxxxx-xxx02-01:e1a complete
Default-3 1500 xx-xxxxxx-xxx02-02:e1a complete

Is this a new feature or a bug, why not just keep it in Default ?

Re: automatic broadcast domain creation ?

Greg_Wilson — Tue, 13 Jul 2021 02:46:59 GMT

Its also doing the same thing for failover groups.

broadcast-domain show -ipspace Default
(network port broadcast-domain show)
IPspace Broadcast Update
Name Domain Name MTU Port List Status Details
------- ----------- ------ ----------------------------- --------------
Default Default 1500 xxx-01:e0M complete
Default-1 1500 xxx-02:e0M complete
Default-2 1500 xxx-01:e1a complete
Default-3 1500 xxx-02:e1a complete
4 entries were displayed.

Re: automatic broadcast domain creation ?

Fabian1993 — Tue, 13 Jul 2021 12:38:00 GMT

Hi @Greg_Wilson,

start with ONTAP 9.8 ONTAP will automatically create Broadcast Domains, also based on Layer 2 reachability.

You can read this here:

https://docs.netapp.com/us-en/ontap/networking/example_of_using_broadcast_domains.html

Re: automatic broadcast domain creation ?

Greg_Wilson — Wed, 14 Jul 2021 00:36:35 GMT

So why does it create a seperate BD for each port ?

Surely you want e0M(management ports) on all clusters to be in the same BD ?

Re: automatic broadcast domain creation ?

Fabian1993 — Wed, 14 Jul 2021 06:35:00 GMT

The system automatically creates any additional broadcast domains during cluster initialization based on layer 2 network reachability. These additional broadcast domains are named Default-1, Default-2, and so forth.

For each Port makes really no sense, in Praxis build the Broadcast Domain by your self..

Maybe than one from NetApp could give us more detailed Information..

Re: automatic broadcast domain creation ?

Mjizzini — Tue, 27 Jul 2021 04:08:57 GMT

It will create a new broadcast domain for every reachable layer2 network.

i recommend configuring the ports on the switches before attaching them with cables.

Example of using broadcast domains

Re: automatic broadcast domain creation ?

Fabian1993 — Wed, 28 Jul 2021 12:57:03 GMT

@Mjizzini

any Plans from NetApp to disable that function? Maybe in the diag mode, is not cool for new Installations 😉