If you are seeking "network admin", "network technician", "network engineer" job which related to Cisco, Junioer, Lucent etc. then the following article will be very helpful and make sure you familiar with those command, tools and principles.

https://www.comptia.org/content/guides/a-guide-to-network-troubleshooting

https://www.geeksforgeeks.org/nokia-interview-experience-set-3/?ref=lbp

https://www.guru99.com/ccna-interview-questions.html

https://resources.infosecinstitute.com/topic/top-50-network-administrator-interview-questions/