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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 9 Configuring Interfaces
Understanding Interface Types
Ethernet Management Port
The Ethernet management port, also referred to as the Gi0 or gigabitethernet0 port, is a Layer 3 host
port to which you can connect a PC. You can use the Ethernet management port instead of the switch
console port for network management.
See the
“Using the Ethernet Management Port” section on page 9-10
for more information.
Switch Virtual Interfaces
A switch virtual interface (SVI) represents a VLAN of switch ports as one interface to the routing or
bridging function in the system. Only one SVI can be associated with a VLAN, but you need to configure
an SVI for a VLAN only when you wish to route between VLANs or to provide IP host connectivity to
the switch. By default, an SVI is created for the default VLAN (VLAN 1) to permit remote switch
administration. Additional SVIs must be explicitly configured.
Note
You cannot delete interface VLAN 1.
SVIs provide IP host connectivity only to the system; in Layer 3 mode, you can configure routing across
SVIs.
Although the switch supports a total of 1005 VLANs (and SVIs), the interrelationship between the
number of SVIs and routed ports and the number of other features being configured might impact CPU
performance because of hardware limitations. See the
“Configuring Layer 3 Interfaces” section on
page 9-19
for information about what happens when hardware resource limitations are reached.
SVIs are created the first time that you enter the vlan interface configuration command for a VLAN
interface. The VLAN corresponds to the VLAN tag associated with data frames on an IEEE 802.1Q
encapsulated trunk or the VLAN ID configured for an access port. Configure a VLAN interface for each
VLAN for which you want to route traffic, and assign it an IP address. For more information, see the
“Manually Assigning IP Information” section on page 3-15
.
Note
When you create an SVI, it does not become active until it is associated with a physical port.
SVIs support routing protocols. For more information about configuring IP routing, see
Chapter 29,
“Configuring IP Unicast Routing,”
and
Chapter 33, “Configuring IP Multicast Routing.”
EtherChannel Port Groups
EtherChannel port groups treat multiple switch ports as one switch port. These port groups act as a single
logical port for high-bandwidth connections between switches or between switches and servers. An
EtherChannel balances the traffic load across the links in the channel. If a link within the EtherChannel
fails, traffic previously carried over the failed link changes to the remaining links. You can group
multiple trunk ports into one logical trunk port, group multiple access ports into one logical access port,
or group multiple routed ports into one logical routed port. Most protocols operate over either single
ports or aggregated switch ports and do not recognize the physical ports within the port group.
Exceptions are the Cisco Discovery Protocol (CDP), Link Aggregation Control Protocol (LACP), and
the Port Aggregation Protocol (PAgP), which operate only on physical NNI or ENI ports.
