Users Guide

Layer 2 Switching Commands 850
In order to enable Private VLAN operation across multiple switches which are
not stacked, the inter-switch links should carry VLANs which belong to a
private VLAN. The trunk ports which connect neighbor switches have to be
assigned to the primary, isolated, and community VLANs of a private VLAN.
In regular VLANs, ports in the same VLAN switch traffic at L2. However for
private VLAN, the promiscuous port is in the primary VLAN whereas the
isolated or community ports are in the secondary VLAN. Similarly, for
broadcasts, in regular VLANs, ports in the same VLAN receive broadcast
traffic. However, for private VLANs, the ports to which the broadcast traffic is
forwarded depend on the type of port on which the traffic was received. If the
received port is a host port; the traffic is forwarded to all promiscuous and
trunk ports. If the received port is community port the broadcast traffic is
forwarded to promiscuous, trunk and community ports in the same VLAN. A
promiscuous port sends traffic to other promiscuous ports, isolated and
community ports.
interface vlan
Use the interface vlan command in Global Configuration mode to enable L3
on a VLAN and enter VLAN Interface Configuration mode. Use the no form
of the command to disable routing on the VLAN.
Syntax
interface vlan {vlan-id}
no interface vlan { vlan-id }
• vlan-id—The ID of a valid VLAN (Range 1–4093).
Default Configuration
By default, Layer 3 is enabled on VLAN 1 on the N1100-
ON/N1500/N2000/N2100-ON/N2200-ON Series switches. However, VLAN
routing interfaces do not route packets until an IP address is assigned to the
VLAN and IP routing is globally enabled. DHCP and Layer 3 are not enabled
on VLAN 1 by default for the N3000-ON, N3100-ON, and N3200-ON Series
switches. DHCP is enabled on VLAN 1 by default for the N1100-
ON/N1500/N2000/N2100-ON/N2200-ON switches. The N1100-ON does not
support routing.