VLANs Flashcards
What are the two trunking protocols?
Inter-Switch Link (ISL) and 802.1Q
What are some of the benefits of VLANs?
- Design flexibility: Can logically group users.
- To segment devices into smaller LANS (broadcast domains), reducing overhead.
- Reduce the workload for STP.
- Enforce better security (separate hosts).
- Separate IP phone traffic from PC traffic connected to the phones.
What does trunking do?
It allows switches to pass frames from multiple VLANs over a single physical connection.
What is the difference in encapsualtion beteen ISL and 802.1Q?
ISL fully encapsulates each original Ethernet frame in an ISL header and trailer.
802.1Q does not actually encapsulate the original frame; instead, it inserts an extra 4-byte VLAN header into the original frame’s Ethernet header.
Which VLAN protocol uses the concept of a native VLAN?
802.1Q
What subnetting rule applies to devices on a single VLAN.
All devices on a single VLAN must be on the same subnet.
A VLAN = a subnet = a broadcast domain.
Do switches using 802.1Q need to have the same native VLAN define?
Yes
What is VLAN Trunking Protocol (VTP)?
A layer 2 messaging protocol that the switches use to exchange VLAN configuration information.
What are the 3 modes of VTP?
Server, client and transparent.
He often do VTP servers and clients send periodic VTP messages?
Every 5 minutes.
What are the 3 types of VTP messages?
Summary advertisements, subset advertisements and advertisement requests.
What are the 3 requirements for VTP to work between two switches?
- Te link between the switches must be operating as a VLAN trunk (ISL or 802.1Q).
- The two switches’ case sensitive VTP domain name must match.
- If configured on at least one of the switches, the two switches’ case-sensitive VTP password must match.
Where are VTP configuration settings stored?
In the vlan.dat file in flash memory.
Where do switches in VTP transparent mode store their VLAN information?
Both in the vlan.dat file in flash and in the running-config file.
What is the main difference between VTP version 1 and 2?
VTP 1 switches in transparent mode discard update information if the domain name and password don’t match. VTP 2 switches in transparent mode forward all update information.
