VLAN Mapping
ISL trunking recognizes only VLANs numbered 1–1001, but 802.1Q can use
VLANs 0–4094. If you are using both ISL and 802.1Q in your network and
have VLANs numbered above 1001, you have to map the 802.1Q VLANS to
ISL numbers. Some rules about mapping VLANs include:
■ You can configure only eight mappings.
■ Mappings are local to the switch; the same mappings must be configured
on all switches in the network.
■ You can map only to Ethernet ISL VLANs.
■ The 802.1Q VLANs with the same number as mapped ISL VLANs are
blocked. (For example, you map 802.1Q VLAN 1500 to ISL VLAN
150, then 802.1Q VLAN 150 is blocked on that switch.)
■ You should not map the 802.1Q native VLAN.