•
If you plan to configure many VLANs on the switch and to not enable routing, you can set the Switch
Database Management (SDM) feature to the VLAN template, which configures system resources to
support the maximum number of unicast MAC addresses.
•
Switches running the LAN Base feature set support only static routing on SVIs.
•
A VLAN should be present in the switch to be able to add it to the VLAN group.
Restrictions for VLANs
The following are restrictions for VLANs:
•
The switch supports per-VLAN spanning-tree plus (PVST+) or rapid PVST+ with a maximum of 128
spanning-tree instances. One spanning-tree instance is allowed per VLAN.
•
The switch supports both Inter-Switch Link (ISL) and IEEE 802.1Q trunking methods for sending VLAN
traffic over Ethernet ports.
•
Configuring an interface VLAN router's MAC address is not supported. The interface VLAN already
has an MAC address assigned by default.
•
The number of VLANs mapped to a VLAN group is not limited by IOS. But if the number of VLANs
in a VLAN group exceed the recommended value of 128, the mobility can be unexpected. So it is the
responsibility of the administrator to configure feasible number of VLANs in a VLAN group. When a
WLAN is mapped to a VLAN group which has more number of VLANs, an error is generated.
•
The static IP client behavior is not supported.
•
Private VLANs are not supported on the switch.
Information About VLANs
Logical Networks
A VLAN is a switched network that is logically segmented by function, project team, or application, without
regard to the physical locations of the users. VLANs have the same attributes as physical LANs, but you can
group end stations even if they are not physically located on the same LAN segment. Any switch port can
belong to a VLAN, and unicast, broadcast, and multicast packets are forwarded and flooded only to end
stations in the VLAN. Each VLAN is considered a logical network, and packets destined for stations that do
not belong to the VLAN must be forwarded through a router or a switch supporting fallback bridging. In a
switch stack, VLANs can be formed with ports across the stack. Because a VLAN is considered a separate
Consolidated Platform Configuration Guide, Cisco IOS XE Release 3SE (Catalyst 3850 Switches)
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Configuring VLANs
Restrictions for VLANs
