I am trying to find the reason where in many Cisco docs, I see the Distribution layer switches in the same switch block interconnected.
e.g. you have a switch block containing two Access layer switches and two Distribution layer switches. Each Access switch has link to both Distribution switches. Also, is the interconnecting link L2 or L3?
Any explanation or links to docs which explain the reason for this would be much appreciated.
No problem with disagreeing. I still think that L2 between the distro switches is a more common setup in the wild regardless of what networkers are saying but happy to admit i could be wrong / out of date :)
I remember the exact same conversation we had when we did MSQ1 and you were surprised when we suggested using a L2 link between our distro switches.
Where i do agree is if all servers/clients etc. are not connected into the distro switches but are on switches connected to the distro switches then yes a L3 link is a good way to go. But often due to cost distro switches double up as server switches because a domain-controller, print server and file-server can't justify an entirely separate pair of switches.
If you had a L2 access-layer you could still use L3 link between distro switches and allow HSRP to run across access-layer links but this have never felt "right" to me.
Like i say i don't think either is right or wrong and removing STP has it's advantages altho with RSTP etc. it's not the villian it used to be but i'm happy to concede that with the right amount of kit L3 is a prefectly good way to go.
Would be very interested to hear from any other engineers on this subject.
Nope, still taking time off and not looking just yet. Hope your'e good and work is still keeping you occupied.