I have the setup which consists of two core and 4 distribution switches, and 4 distribution switches is connected with both core switches in redundant links.
First of all let me tell u what ever concepts i have, if wrong please correct me!
I have configured management vlan1 interface with 10.1.1.1/24 in core1 and 10.1.1.2/24 in core2 and my hsrp IP for vlan 1 is 10.1.1.100/24, which I have used as a gateway for DIS 1,2,3,4.
management IP for Dis1 ( 10.1.1.3) - Dis (10.1.1.4) - Hsrp IP for these distribution switch is 10.1.1.5 which i have used as a gateway in 1st two access switches.
I have configured vlan 20,30,40,50 in core 1(vtp server) and gave the ip 18.104.22.168/24(vlan 20), 22.214.171.124/24(vlan 30), 126.96.36.199/24(vlan 40), 188.8.131.52/24(vlan 50) in CORE1
ip 184.108.40.206/24(vlan 20), 220.127.116.11/24(vlan 30), 18.104.22.168/24(vlan 40), 22.214.171.124/24(vlan 50) in CORE2
HSRP IP for vlan 20 ( 126.96.36.199), vlan 30 ( 188.8.131.52), vlan 40 ( 184.108.40.206), vlan 50 ( 220.127.116.11). I have used these ip's as gateway for my pc in respective vlan's.
My concern is, If i run L3 links between distribution switch and core, what all changes I have to make?
If possible please help me with learning the diff between L2 and L3 links between L2 and L3 links between switches!!
Please advice - waiting for your valuable answers - need help!!
This is a lot of work.
If you have L3 between the core and the distro switches then all the vlan info and L3 inter-vlan routing + HSRP needs to be migrated off the core to the distro switches.
However it's not that straightforward. At the moment because the links are L2 you can have the same vlan across all four distro switches. If you migrate to L3 then you need to have 2 pairs of distro switches. Each pair of distro switches would be interconnected via either a L2 trunk or a L3 link. Either way you will not be able to have the same vlan on both pairs of switches because there is now no L2 adjacency between all 4 distro switches unless you carefully plan your access-layer switch uplinks and use these as transit links but that would get very messy.
Basically you need to understand exactly how you would allocate vlans to distro switches before even starting to plan a migration otherwise you could do some serious damage.