Top-of-rack, describing the switch at the top of each rack to which its hosts are cabled. Each ESX host in VCF needs a link to one switch as a minimum, though two or more are advised; their first-hop gateway must then run on every switch or move between them on failure.
Also called top-of-rack.
Read more: Broadcom TechDocs
In the Ultra Transcenders books
Each book explains ToR in context, with comparison tables and the common traps.
Terms in this definition
- SWITCH
Checks one expression against several candidate values, returning whichever result pairs with the match (or a fallback otherwise). Writing SWITCH ( TRUE (), ... ) avoids nested IF chains: whichever condition is first true wins.
- ESX
VMware's bare-metal hypervisor, installed on each host in a VCF fleet. Up to version 9.0 it was known as ESXi.
- VMware Cloud Foundation
Broadcom's platform for private cloud. It unifies management of NSX, vSAN, vSphere, VCF Automation and VCF Operations as one fleet; VVF, by contrast, lacks automation and cloud management.
- First-hop gateway
The router that traffic reaches first on leaving a VLAN segment. VCF needs the data centre to supply one, with an appropriate MTU, for each infrastructure VLAN, and advises using a VRRP or HSRP virtual address that stays available through any failure the cluster model is designed to withstand.
Related terms
- Anonymous IP address
Sign-in risk detection in Microsoft Entra ID Protection, raised when someone signs in through an anonymising proxy like Tor.
- Dual Availability Zone Design based on NSX Edge Node HA
Unlike the vSphere HA recovery design, where edges migrate between zones, this two-zone NSX Edge cluster model fixes each edge node to one zone, on either a per-zone vSphere cluster or a stretched vSAN cluster. Edge VLANs stay local and BGP peers only with that zone's top-of-rack switches, while NSX Edge node HA and BFD provide rapid failover and the strongest fault isolation.
- Link aggregation group
Several physical switch ports acting as a single logical link. A balance-tcp bond requires this, with LACP, to be turned on at the top-of-rack switch.