Link Aggregation

FR4X

Hello,

I have a question about link aggregation configuration on SonicWall. I know that to configure a LAG on a SonicWall firewall I need to add an IP address for the aggregator port, but what's the purpose of that IP? Is it used for any routing? If I configure virtual interfaces under the LAG, do the subnets for those virtual interfaces have to be related to the aggregator port IP? I'm asking because this is new to me, I never had to add an IP to a physical member of the LAG to be able to configure it on any other appliance I used before. Thanks in advance.

Firewalls_com

Hello FR4X,

The firewall is a router and the gateway for your local network. My assumption is you aren't wanting to assign the physical port a network and plan on just using VLANs. What is the use case for not having a native vlan?

The LAG interface can be aggregated to an unassigned port that is a parent interface for vlans.

"If I configure virtual interfaces under the LAG, do the subnets for those virtual interfaces have to be related to the aggregator port IP?"

No. The vlan interface IPs act as the gateway for the traffic for hosts connected to a switch where the ports are tagged with the appropriate vlan. The vlans are only related to the physical port subnet in that the traffic shares a physical port and wire.

FR4X

This answers my question, thank you for your help!

Firewalls_com

You're welcome FR4X. Just make sure there are no VLANs already assigned to the port prior to choosing it for aggregation. It will allow you to add VLANs after the aggreation is complete.

SWSelf

Is this the lagg done via Networking > Switching > Link Aggregation as I have ports without IP addresses and they are not showing up in there - the frustrating thing is I have done it on 2 other exact setups without issue