If we have a fully functioning Layer 2 Aggregate Switch network and want to minimise downtime in switching to Layer 3, can we go ahead and create these VLAN Interfaces without it affecting the network until we're ready to cut-over to Layer 3 (and then switch to Warm Spare (VRRP)?
We currently have 2 x Meraki MS425 Aggregation switches with a bunch of MS225 edge switches connected via LACP. The 2 x MS425 Aggregation Switches are currently connected to old and fear of failing 2 x Catalyst x3750's which currently are in place for the purpose of routing traffic at Layer 3!
Our plan is to configure Layer 3 Switching on the Meraki 425's and switch them to a Warm Spare VRRP setup (accepting that we'll lose our 20Gbps aggregation to edge switches, down to 10Gbps.)
This should then hopefully allow us to remove the aging Catalyst x3750 stack.
The Warm Spare setup will have the "Primary" MS425 connected to our Preferred NCS/WAN (1gb/1gb) connection, and the "Spare" MS425 connected to our Backup NCS/WAN connection (1gb/1gb).
I'm really a novice on this interesting topic so I'm wondering if someone could answer a very basic question regarding VLAN creation.
Let's say you have one large VLAN of 192.168.40.0/22 (default VLAN 1) and you wish to break that up into smaller VLANs - say 10 (10.1.10.0/24) and 20 (10.1.20.0/24). The router is 192.168.40.1
I think my question is, what happens to the default VLAN 1 if you want to keep that subnet of 192.168.40.0/22 as the transit VLAN as was described in the video? I'm assuming you can't just simply create a new SVI for 192.168.40.0/22 and assign it VLAN 40 since it is already in use as the default VLAN 1.
I hope my question makes some sense. I'm missing something obvious here so thank you kindly for any insights on this.