Unit 7 Text

TEXT OF UNIT 7

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· About routing:

Dynamic routing protocols are classified into two major categories: (1) distance vector protocols and link-state protocols.

Routers running distance vector routing protocols share network information with directly connected (2) routers. The neighbor routers then (3) advertise the information to their neighbors, until all routers in the enterprise learn the information. A router running a distance vector protocol does not know the entire (4) path to a destination; it only knows the distance to the remote network and the direction, or vector. Its knowledge comes through information from directly connected neighbors.

Like all routing protocols, distance vector protocols use a (5) metric to determine the best route. Distance vector protocols calculate the best route based on the distance from a router to a network. An example of a metric used is (6) hop count, which is the number of (7) loops, or hops, between the router and the destination.


· About RIP:

The RIP distance vector routing protocol is easy to configure and (8) requires minimal amounts of router resources in order to function.

However, the simple hop count metric used by RIP is not an (9) accurate way to determine the best path in complex networks. Additionally, the RIP limitation of 15 hops can mark distant networks as unreachable.

RIP issues periodic updates of its routing table, which consumes (10) bandwidth even when no network changes have occurred. Routers must accept these (11) updates and process them to see if they contain updated route information.

Updates passed from router to router take time to reach all areas of the network. As a result, routers may not have an accurate picture of the network. Routing (12) neighbors can develop due to slow (13) convergence time, which wastes valuable bandwidth.

These characteristics limit the usefulness of the RIP routing protocol within the enterprise environment.


Words: advertise , routers , accurate , neighbors , bandwidth , convergence , loops , metric , updates , distance , path , hop , requires

Vocabulary and questions about Google data center

QUESTIONS: 

In today's activity, you have to watch this 7-minute video about security on Google Data Centers. Follow these suggestions:

the use of subtitles are strongly recommended.

write down all the words that you don't understand.

go slowly, trying to understand each sentence and the overall meaning of the speech.

Once you have carefully watched the video, the following set of questions: 

1) What are the main security measures showed by the video when accessing the building?

·         Restricted barrier for vehicle access

·         Security fencing around the perimeter

·         Security personal 24h/7w

·         Monitoring cameras

2) What is the security technology related to "sight" that Google uses for accessing the core part of the facility?

Biometric devices and badges.

3) According to the video, what type of device is indispensable to Google's usual day-to-day activity?

Hard drives

4) What two actions do Google's technicians do when a hard drive fails?

It’s reformatted, retested and overwritten

5) What two actions do Google's technicians do when those hard drive that have ended their "life cycle"?

Google have a crusher for making hard drives unreadable and a shredder for complete this process.

6) How does Google manages to have permanent connectivity to the internet backbone?, what is the concept that is referred to in the video?

Google have his data centers connected via high speed fiber-optic cable with redundant connections to fix a single connection down.

7) How does Google manages to guarantee the safety of stored data?

Google maintains an extra backup and robust fire detections and suppression capabilities.

8) How does Google manages to guarantee the continuous power supply?

Using emergency backup generators

9) What does Google want specifically to check by using video cameras?

It wants to detect anomalies such as potential intruders

10) What kind of "raw material" is Google committed not to use?

Carbon

Vocabulary:

Comprehensive: exhaustivo

Roster: lista

Measures: medidas

Shredder: trituradora

Crusher: machacador

Badge: Tarjeta