10-18-2011 05:33 AM
I am much familiar with multiport trunking ( to me it was trunking) and recently i learned that there is a VLAN trunking too. Could some one explian in simple what is VLAN trunking and if possible with an analogy. if this is not a Brocare terminology what is this called here?
10-18-2011 05:45 AM
Yes trunk is a multiple used expression.
With VLAN trunking is meant that multiple 802.1Q VLANs are transmitted tagged from one switch to another switch.
tagged means that the ethernet packets include the 802.1Q VLAN tag field for identifying and transporting the VLAN ID between switches.
switchport mode trunk
switchport encapsulation dot1q
Trunking is also often used for combining multiple ethernet ports together to one logical port for increasing bandwidth and having load balancing and redundancy.
Cisco names this port-channel others say LAG (Link Aggregation Group)
This could be run static (without any protocol, Cisco = mode on) or dynamic with LACP protocol (Cisco = mode active).
Brocade has static LAGs called trunk in the config and have dynamic LAGs with LACP called "link-aggregate" in the config of FastIron or LAG on Netiron.
Hope this helps