I have been going through the community forums looking for a specific answer or example of my question but I wasn’t able to find the correct wording apparently so please forgive me if this has already been asked/answered about Intervlan routing.
My setup for this scenario is the following :
Desktop in vlan 10 (Will get IP 10.1.1.x/24) -> layer2 switch -> layer3 switch in closet (IP 10.1.1.7/24) -> Distro switch layer 3 (IP 10.1.1.5/24) > Core switch (IP 10.1.1.1/24)
VTP domain and trunking throughout.
DHCP scope for the Desktop will be giving the Default gateway of 10.1.1.1/24
The destination for this scenario will be a server that is off the layer 3 switch in closet in vlan 20 on another layer 2 switch. The layer 3 switch (in closet) has an IP for vlan 20 also.
Now my understanding of the using ‘IP routing’ command will allow intervlan routing on layer 3 switches but all the examples show one switch deep and using .1 as the gateway. I want to confirm that even though the gateway for the desktop is still .1 the path or the majority of the path of the data and connection will stay local to the first layer 3 switch (in closet) or will it always go to the gateway IP (Core) before coming back down?
If the layer 3 switch is on the same closet (in building A), why is the default gateway pointing to the core in building B ?? Can you have the layer 3 SVI's directly configured on the layer 3 switch in building A ? If the default gateway is pointing towards the core in building B, then obviously the packets would travel on layer 3 till core (Blg B), and then come back... in order to avoid this, you can configure the def gw on the layer 3 switch which is on the same closet as layer 2, and make it a distribution switch.. this also would allow you to have your spanning tree domain isolated in building A, which means that if you have a layer 2 attack or virus in blg A, it would affect the users in bldg B (based on the traffic pattern)..
Hope this helps.. all the best