Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
VLAN |
Virtual Local Area Network |
|
|
VTP |
VLAN Trunking Protocol |
|
|
VTP Operating Mode |
Server: Default Transparent: Disables VTP Client: Allows switches to inherit the VLAN information from a server(s). Cannot create VLAN's locally on a VTP Client device |
|
|
show vlan (brief) |
Useful for verifying VLAN's |
|
|
default vlan |
VLAN 1 is the default VLAN on Cisco switches and all non-trunk ports are listed as participants of this VLAN, it is a best practice to remove all ports from this default VLAN. While by default two hosts connected to the same switch will be in separate collisions domains, both will be part of the same layer 2 broadcast domain and VLAN |
|
|
switchport cmd. |
used to assign ports to a VLAN interface gi0/1 switchport mode access switchport access vlan 20 end |
|
|
Voice VLAN config |
vlan 30 name WEST vlan 50 name VOICE exit interface gi0/2 switchport mode access switchport access vlan 30 switchport voice vlan 50 end note that Cisco Discovery Protocol (CDP) is required for IP phones to function, but CDP is often enabled by default |
|
|
show interface gi0/1 switchport |
A powerful command displaying information regarding the interface configuration, including the Voice VLAN |
|
|
Trunking |
A normal port (access port) may only be assigned one VLAN at at time. A trunk port may support multiple VLAN's, a port connecting one switch to another would be configured as a trunk |
|
|
ISL |
Inter Switch Link, older method used by Cisco to move traffic of different VLAN's from switch to switch Encapsulated entire frame in order to add a VLAN marking |
|
|
802.1Q trunk link |
Most common ethernet trunking protocol in use today Used to move traffic of different VLAN's from switch to switch. Injects a tag value into an existing frame, between the source MAC address and type fields of the frame header, which allows multiple VLAN's to be supported over a single trunk interface |
|
|
TPID |
Tag protocol identifier a 16-bit field set to a value of 0x8100 in order to identify the frame as an IEEE 802.1Q-tagged frame |
|
|
TCI |
Tag control information, consists of the following -Priority Code Point (PCP): A three-bit field that refers to the IEEE 802.1p class of service and maps to the frame priority level -Drop eligible indicator (DEI): A one-bit field that may be used in conjuction with PCP to indicate frames eligible to be dropped in the presence of congestion VLAN identifier (VID): A 12-bit field specifying the VLAN to which the frame belongs |
|
|
Configuring 802.1Q trunking |
interface gi1/0 switchport trunk encapsulation dot1q (sets dot1q as the protocol) switchport mode trunk end |
|
|
Native VLAN |
The native VLAN is not tagged, the only untagged VLAN in the infrastructure, by default it is VLAN 1 Used for management traffic which will continue to flow between devices even if a link loses its trunking status. CDP messages are sent over the Native LAN by default |
|
|
CDP |
Cisco Discovery Protocol, is a level 2 service which allows cisco devices to communicate information about each other to their directly connected neighbors Useful when you are unsure of the topology Used by cisco IP phones to communicate their capabilities and VLAN information to their local switch CDP messages are not forwarded enabled by default |
|
|
CDP (contd.) |
To ensure that CDP is active configure terminal cdp run (enables cdp globally) interface gi1/0 cdp enable (enables cdp on interface) end though useful, CDP presents a potential security risk, it is often disabled on public facing interfaces |
|
|
LLDP |
Link Layer Discovery Protocol, is an open standard approach that serves the same basic purpose as CDP, thought it is not enabled by default of cisco switches. To activate; configure terminal lldp run interface gi1\0 lldp transmit lldp receive end |
