07-30-2023 03:33 AM
DAD link prevents both supervisors from becoming active in event of a VSL link failure.
My question is - do I need DAD link. if I have 4 x 100G ports configured as VSL links?
I need other ports for access switches.
My core switch - 9500-24Y4C
07-30-2023 04:28 AM - edited 07-30-2023 04:28 AM
It optional cisco recommends but not mandatory.
DAD dont carry any mgmt/control/data traffic it only use for heartbeat.
07-30-2023 07:01 AM
Hi @uppermost
I believe the terminology here might be important.
VSS, VSL and DAD X StackWise Virtual, SVL
VSS, VSL and DAD is suiltible for IOS device like 6500, 6800, etc.
Stackwise Vitual and SVL is suitible to IOS-XE like 9500,9300,etc
As we are still handling both kind of device and many companies are migrating or preparing to migrate ( 6807-XL Last Date of Support: HW is 2027!) both concept are still present.
But, Stackwise vitual is a new way to perform VSS and it does not required DAD. The link beween devices is now called SVL and it is more like a tradditional stack.
Reading the document for StackWise Virtual we start to see afirmation like "only", "cannot", etc.
On C9500-32C switches, you can configure SVL and DAD only on interfaces numbered 1-16 on the front panel of the switch.
On C9500-32QC, you can configure SVL and DAD only on native 100G and 40G interfaces (default configuration ports). You cannot configure SVL and DAD on converted 100G and 40G interfaces.
In a Cisco StackWise Virtual solution, ports that support 4X10G breakout cables can be used only as data-only ports and cannot be used for configuring SVLs or DAD links.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide