ISL+&+802.1q

ISL encapsulates 802.1q inserts tag and supports native VLANs

=Configuration=

config-if# switchport mode (DTP negotation params) config-if# switchport trunk (trunking params) config-if# switchport access (non-trunking params)

=View/Debug Commands=

show interface trunk

=Trunk Configurations=


 * **Trunk** - mode trunk; sends dtp
 * **Nonegotiate** - mode trunk; nonegotiate; no dtp
 * **Desirable** - mode dynamic desirable; sends dtp
 * **Auto** - mode dynamic auto; replies to dtp
 * **Access** - mode access; never trunks
 * **Access & Nonegotiate** - mode access; nonegotiate; never trunks

=Routers=

No DTP Use subinterfaces for each VLAN

config-if# encapsulation dot1q [native]

=802.1Q-in-Q Tunneling=

Additional 802.1q frame with customer specific VLAN id Travels over WAN Supports CDP & VTP