Network Management

 

Learning Outcomes:

• Develop the basic skills of monitoring and fine-tuning the performance of a simple network.
• Students should be able to use some simple network monitoring software to interrogate devices to determine their status and to obtain statistics about the networks for monitoring and fine-tuning purposes.
• Develop the basic skills of analyzing problems of a networked environment and performing troubleshooting for it.
• The problems may involve cabling, Network Interface Card (NIC), driver, Network Operating System (NOS), and configuration of a network, etc.
• Be aware of the importance of backup in disaster planning and recovery measures.
• Know the common hardware and software components of a network backup solution.
• Students should be introduced to the different components/technologies of a network backup solution including network backup servers, network backup and recovery software, Uninterruptible Power Supply (UPS), and Redundant Array of Independent Disks (RAID), etc.

 

Network performance

• Proxy server can improve network performance by caching a copy after a website being visited.
• This does not happen if
• First time visit (no local copy)
• Connection via HTTPS (no cache for HTTPS connection unless special configuration made)
• Live streaming

 

• Wireless network speed can be affected by
• Hardware – e.g. old standard WiFi router, access point location
• Interference – from channels with significant overlap
• Number of connected devices – sharing of bandwidth
• Network configuration – maximum speed is set

 

• Network speed can be affected by
• Cable vs wireless network
• Hardware – older devices/routers
• The service provided by ISP
• Computer processing power – both the client and the server
• Network traffic

 

Relevant past paper:

DSE ICT Elect B(SP-2017): 2013 2ci. 2014 3biii. 2017 2b.

CE CIT Elec C(2005-2011): 2007 2diii, 4dii. 2008 3c, 4b. 2010 3aii.

 

Network troubleshooting

 What to check

• Hardwares e.g. network interface card, cable, router
• Command tools
• Ipconfig: check the values of current default gateway and IP address
• Ping: check connectivity. Whether it can reach certain IP address.
• Tracert: show the details about the path that a packets take from the computer to destination.
• Nslookup: look for any DNS server issue. (or visit different websites)
• Other issues
• Port number related: e.g. Visit websites with different port number e.g. HTTPS, HTTP
• Device configuration: e.g. firewall setting
• Website related: e.g. web server issues, DNS server errors
• Network congestion

 

Relevant past paper:

DSE ICT Elect B(SP-2017):  SP 4c. PP 2bc. 2016 4c.

CE CIT Elec C(2005-2011): 2008 3fii. 2009 2e.

AS CA(2000-2013): 2011 8f.

 

Network backup solution

 

• Uninterruptible Power Supply (UPS)
• Functions: 
• Protect against power failure by providing temporary power supply
• Protect against voltage drop by providing stable power supply
• During power interruption, UPS allows time for 
• backup creation
• the computer/server can shut down properly.

 

• Redundant Array of Independent Disks (RAID)
• Two or more drives working in parallel
• RAID 1 – mirroring: both drives have the same set of data. Requires at least 2 drives.
• RAID 5 – striping with parity: the data are striped across the drives together with parity data.  Requires at least 3 drives
• RAID 10 – combining RAID 1 and RAID 0 (mirroring + striping). Requires at least 4 drives
• These RAID configurations can protect against single drive failure. (but not RAID 0)

 

• Backup medium
• Magnetic Tape: Large amount of data with low cost
• Second Hard drive for RAID 1: see above
• External Hard drive: portability
• Network attached storage: storage with network capability. Essentially a drive within your network. Additional features may include access control, RAID and UPS.
• Cloud storage: Storage managed by third party and accessible through the internet.
• Advantages: Maintenance also by third party. Choose storage size according to need.
• Disadvantages: Security concern. Requires internet access.

 

• Backup
• How?
• Full backup: all data are copied.
• Advantages: easy to recover the data when needed.
• Disadvantages: slow backup time.
• Incremental backup: record the changes since last backup.
• Advantages: fast backup time.
• Disadvantages: slow recovery time. To restore data, need to have full backup copy + all incremental backup copies.
• When?
• Usually overnight, when the server/computer usage is low.

 

Relevant past paper:

DSE ICT Elect B(SP-2017): PP 2a. 2012 4c. 2013 4d. 2014 1f. 2015 2d, 4b. 2016 2abcii,iii. 2017 1e.

CE CIT Elec C(2005-2011): 2007 3d.

AS CA(2000-2013): 2003 10e. 2007 9c. 2008 10f. 2010 9a. 2013 4.

 

References:

https://network-data-cabling.co.uk/blog/Wi-Fi-17-factors/

https://www.techguide.com.au/news/10-things-affecting-internet-speed/

https://www.dnsstuff.com/network-troubleshooting-steps

https://www.ia.omron.com/support/guide/572/introduction.html

https://www.prepressure.com/library/technology/raid

https://www.aomeitech.com/nas/what-is-nas-storage-and-how-it-works-1234.html

http://www.nssit.com/how-to-choose-a-data-backup-medium/

https://www.business.org/it/cloud-computing/cloud-vs-network-attached-storage-pros-cons/

https://phoenixnap.com/kb/full-vs-incremental-vs-differential-backup

https://cloudpockets.com/best-time-to-backup/