Infrastructure Services Flashcards
What type of protocol is HSRP
First Hop Redundancy Protocol FHRP
What are the 3 main FHRPs
HSRP hot standby router protocol
VRRP virtual router redundancy protocol
GLBP gateway load balancing protocol
What are the default HSRP hello/dead timers
3/10
How does HSRP work
By using a virtual IP and MAC
What is GARP
Gratuitous ARP - an arp message that wasn;t asked for
What do all 3 FHRPs have in common
Redundancy focused
Virtual ip and macs
Keep alive timers
Which two FHRPs are cisco proprietary
HSRP
GLBP
What is the virtual mac address of HSRP ver 1
0000.0c09.ac–
What is the virtual mac address of HSRP ver 2
0000.0c9f.f—
What is the difference between HSRP ver 1 & 2
With ver 2, the hello timer can be set in milliseconds, ver 1 can’t.
Ver 1 and 2 are not compatible with each other
How is HSRP configured
- Go to interface
- Standby version 2
- Standby 1 ip 10.1.55.1
- Standby 1 priority 150
- Standby 1 preempt
What is preemption
it means that router regains primary router status should failover occur and issue be fixed.
In HSRP, how is the primary router elected
By setting a higher priority
What is Qos
Quality of service
The ability to dictate traffic treatment o Prioritization o Shaping / policing o Advanced strategies (WRED) Strategies to fight the enemy o Delay o Jitter (differing delay between packets) o Packet loss
What are the Qos audio requirements
- Jitter < 30ms
- Delay < 150 ms
- Loss < 1%
- Qos: dscp ef
- Bandwidth:little
What are the Qos video requirements
- Jitter < 30ms
- Delay < 150 ms
- Loss < 1%
- Qos: dscp af41
- Bandwidth: lots
What are some QOS tools that can be used.
Methods available o Classification and marking o Queueing (congestion management) o Congestion avoidance o Shaping and policing Understand trust boundary
What is classification
identifying what the traffic is.
What is marking
= figures what the traffic is and puts a class of service (L2) or type of service (L3) in header
What is taildrop
when packets are dropped because devices queue is full
What is congestion avoidance
tries to prevent queueing in first place e.g WRED, when router selectively drops certain pieces of web traffic to stop queue from filling up, to allow mission critical traffic
What is shaping
takes traffic that you want and curve it down, stops from consuming whole bandwidth
what is Policing
dropping traffic we don’t like
What are the identification tools and what are the action tools
Classification and marking = identification tools
Queueing, congestion avoidance, shaping & policing = action tools
Why is it beneficial to move the network trust boundary closer to the end device?
- Because more devices perform the work of classification and marking
What are the main queueing strategies
WFQ Weighted fair queueing
CB-WFQ classed based WFQ
LLQ low latency queueing
What is WFQ
Weighted fair queueing (WFQ) – low traffic senders get priority over high traffic senders
What is CB-WFQ
Class based WFQ – divides bandwidth among classes you define
What is LLQ
Low latency queueing (LLQ) – combo of CB-WFQ, but adds a strict priority element, also called PQ-CBWFQ (Priority queue – class based weighted fair queueing)
Where should a standard ACL be placed
Close to destination
Where should an extended ACL be place
Close to source
