Vol 1 Part 3: Implementing Ethernet LANs Flashcards
How do you changes the bridge ID manually for an interface?
By using the priority command
How does a switch determine which port will be the root port?
All of the links from that port to the root bridge are added together. The lowest value wins, and that port is now the root port.
What is the vendor neutral EtherChannel version known as?
Link Aggregation Control Protocol (LACP)
In Rapid STP, what state replaced the disabled, blocking, and listening states?
Discarding state
What protocol governs trunking ports?
802.1Q
What command do we use when we want to see all the the VLANs in the VLAN database and which port they are assigned to?
Show vlan brief
The priority multiple is in multiples of what number?
4096
What are the two types of STP?
802.1d and 802.1w (aka the newer and faster protocol. Also known as rapid STP).
The non-root switches require to have what between itself and the root switch?
Administrative distance
RSTP has 5 roles and 3 states. What are they?
Roles: Root, alternate, designated, backup, disabled
States: discarding, learning, forwarding
Who owns the VLAN Trunking Protocol (VTP)?
Cisco
What are the different cost values with STP?
1, 2, 19, 100
STP uses roles and states. What are the 3 roles and what are the 5 states?
Roles: root, designated, blocking
States: listening (blocks and does not forward), learning (blocks and does not forward, but learns the MAC addresses of frames received), blocking, forwarding, disabled.
What is required when connecting multiple switches that will pass multiple VLANs?
Trunking
A tag contains what with respect to the VLAN?
The VLAN ID, also known as the VLAN number
What is BPDU guard and why do we use it?
Disables a port if any BPDUs are received. This is good for ports that are supposed to be access ports and helps prevent attacks and people dropping in on a switch to take over the network.
What is the max age for hellos in STP and RSTP?
STP: 10 times the hello timer (20 seconds by default)
RSTP: 3 times the hello timer (6 seconds by default)
How are VLANs identified on the trunk link?
A tag
What command do you use to enable EtherChannel?
channel-group “number” mode on
Remember to use the same number for all commands on the same switch you are configuring EtherChannel on. The channel-group number need not be the same from switch to switch however.
What does PortFast do?
It puts a switchport into forwarding mode immediately
What is load distribution/balancing with respects to EtherChannel?
Balance traffic across active links to prevent hardware from being overwhelmed and slowing down. This creates a faster and more efficient network.
What is Dynamic Trunking Protocol (DTP)?
Determines if the port should be trunking or not by sending DTP messages
What does a designated port do?
It is a port that can be utilized to communicate between switches.
Two VLANs exiting on a single switch indicates what with respect to broadcast domains?
We have two broadcast domains. In a sense, we have two switches on one switch.
What items must be the same for interfaces to participate in port-channel (EtherChannel)?
Speed, Duplex, Operational State (access or trunk), access port and access VLAN, trunk port and allowed VLANs, trunk port native VLAN, STP interface settings
What is the default mode for load balancing known as?
src-mac
ex. port-channel load-balance src-mac
After a root bridge is elected, what will STP do with all of the interfaces on the switch?
The interfaces are all put in a forwarding state
What does the switchport access command do?
It assigns which specific VLAN we are referencing with regards to the mode we are giving it