After the city adds a new spine, traffic still avoids it. What unde…

Question

After the city adds a new spine, traffic still avoids it. What underlay routing condition must be true for the new spine to join ECMP?

Accepted Answer

The new spine must participate in underlay routing with correct path costs so leaves install it in the equal-cost multipath set — A dark spine with no routing story is just an expensive shelf. It has to peer, advertise, and cost the same—or better, equally—before ECMP invites it to the party. Cable glow is not enough.

Answer

The new spine only needs power and Layer 1 light; routing adjacency is optional for ECMP

Answer

Leaves must disable BGP multipath until the new spine is the STP root

Answer

All existing spines must be shut down so traffic is forced onto the new spine first

After the city adds a new spine, traffic still avoids it. What underlay routing condition must be true for the new spine to join ECMP?

Short Explanation

Full Explanation