I have seen a lot of discussion about VLANs in the Suggestions section of the Canopy forums. I have heard of VLANs but have no experience in using them so I decided to do some reading to learn about them. I found a great tutorial on the web, and a few questions have come up that I was hoping some VLAN experts could address.
From what I read, it seems that VLANs are typically implemented in managed switches. I saw that one of the general reasons for placing hosts on VLANs is to limit broadcast traffic. Broadcast packets from a member of a VLAN will only be seen by other members of that same VLAN where the packet originated.
Suppose there are four hosts connected to a managed switch that is capable of doing VLANs. Two machines are on VLAN1, and the other two are on VLAN2. Also suppose that a Cisco Fast Etherenet Interface is connected to this same switch, and it is NOT a member of VLAN1 or VLAN2.
If a host on VLAN1 needs to broadcast for the IP address of the Cisco Interface in order to get out to the Internet, I am assuming that the broadcast packet will never reach the Cisco because it will only be seen by the other member of VLAN1. Does this mean that the Cisco interface port on the switch also needs to be a member of VLAN1 to receive this broadcast packet?
Assume the same situation coming from a host on VLAN2. Does the Cisco Interface have to be a member of VLAN2 also? Is is possible for a port on a VLAN capable switch to be a member of multiple VLANs?
Thanks in advance.
Yes, your switch’s port (or router or pc) can be a member of multiple VLANs if it supports 802.1Q (vlan tagging).
As VLAN frames contains the VLAN id, of the unit supports 802.1Q (tagging) it can ‘decode’ the VLAN packets.
That means, you have sales and technican guys in the office, sharing the same ethernet, server, and switch, but sales uses 10.0.1.0/24 and tech. uses 10.0.2.0/24.
There are two ways to handle this project: server with 2 eth ports, connecting to each VLAN, or 1 eth port with 802.1Q support and a switch with 802.1Q support. If you choose the last, your server will have 2 virtual interfaces within 1 real.
AS Canopy is transparent for VLAN (doesnt care about tagging, just passing it) we are waiting for a support to separate the ethernet frames between residental and business customers (for example). At the moment we have to use a tagging capable switch to solve this problem.