Information Technology Reference
In-Depth Information
Port/Port Group
A logical object on a vSwitch that provides specialized services for the
VMkernel or VMs. A virtual switch can contain a VMkernel port or a VM port group. On a
vSphere Distributed Switch, these are called distributed port groups.
VMkernel Port
A specialized virtual switch port type that is coni gured with an IP
address to allow hypervisor management trafi c, vMotion, iSCSI storage access, network
attached storage (NAS) or Network File System (NFS) access, and vSphere Fault Tolerance
(FT) logging. A VMkernel port is also referred to as a
vmknic
.
No More Service Console Ports
Because vSphere 5.5, like vSphere 5.0 and 5.1 before it, does not include VMware ESX with a tradi-
tional Linux-based Service Console, pure vSphere 5.
x
environments will not use a Service Console
port (or
vswif
). Instead, the functionality of a Service Console port in ESX 4.
x
and earlier is handled
by a VMkernel port in vSphere 5.
x
.
VM Port Group
A group of virtual switch ports that share a common coni guration and
allow VMs to access other VMs or the physical network.
Virtual LAN
A logical LAN coni gured on a virtual or physical switch that provides efi -
cient trafi c segmentation, broadcast control, security, and efi cient bandwidth utilization by
providing trafi c only to the ports coni gured for that particular virtual LAN (VLAN).
Trunk Port (Trunking)
A port on a physical switch that listens for and knows how to
pass trafi c for multiple VLANs. It does this by maintaining the 802.1q VLAN tags for trafi c
moving through the trunk port to the connected device(s). Trunk ports are typically used
for switch-to-switch connections to allow VLANs to pass freely between switches. Virtual
switches support VLANs, and using VLAN trunks allows the VLANs to pass freely into the
virtual switches.
Trunking vs. Link Aggregation?
You might, depending on your networking vendor, also see use of the term
trunk
to describe an
aggregation of multiple individual links into a single logical link. In this topic, we use
trunk
only to
describe a connection that passes multiple VLAN tags, and we'll use the term
NIC
teaming
or
link
aggregation
to refer to the practice of bonding multiple individual links together.
Access Port
A port on a physical switch that passes trafi c for only a single VLAN. Unlike a
trunk port, which maintains the VLAN identii cation for trafi c moving through the port, an
access port strips away the VLAN information for trafi c moving through the port.
