Network Engineer Interview Questions

General - -Describe whether you are a network admin or server admin?
-Are you currently or have you worked as a member of a team? If yes, name some of the challenges and how you handled them. Are you currently or have you worked as a member of a team? If yes, name some of the challenges and how you handled them.
-Do you prefer routing or switching?
-What are your strengths and weaknesses?
-How do you troubleshoot network slowness issues?

Switching -
-On a Cisco switch, when would you use a "ip default-gateway" command, and when a default route ip route 0.0.0.0 0.0.0.0 x.x.x.x
-You create an SVI on 3560 switch, and its IP does not respond to ping. What could be the problem?
-On 3560 switch -What command would you use to view the mac table?

-On 6500 switch(IOS) - What command would you use to view the mac table?
-On 6500 switch(CATOS) - What command would you use to view the mac table?
-On Foundry(FOS) - What command would you use to view the mac table?
-What is the Native Vlan?
-3750 Switch-stack: which switch's flash holds the image that will run in
RAM when the stack is powered-up?
-What commands would you use to set up a trunk between 2 cisco switches
-What commands would you use to set up a trunk between 1 cisco switch and 1 cisco router
-Difference between BPDUGUARD/BPDUFILTER
-Explain how STP works
-What is spanning tree protocol and how does it work?
-Difference between a trunk and an access layer switch port?
-Two PCs attached to 2 different switches. The switches are connected to each other but the PCs can't ping each other. Possible reasons? Steps to troubleshoot?
-Link status is up, but line protocol is down - what's wrong?
-You have a switch that won't power on. How do you get it replaced?
-Describe how multiple VLANs can exist on a single switch link
-Name a trunking protocol you have used and how it works (

Routing -
-OsPF- configuration statement
-HSRP - what is "interface tracking" used for ?
-Which has a higher admin distance- EBGP(20) or EIGRP(90)
-Which has a better admin distance- EBGP or EIGRP
-BGP- When would you apply a Weight to a BGP neighbor?
-BGP- When would you prepend an AS path?
-BGP- If you prepend a prefix's AS Path, does the prefix look better or worse to the world?
-BGP- What command would you use to see your BGP neighbors?
-BGP- Who controls routing with an AS?
-EIGRP-Do Juniper routers run EIGRP?
-EIGRP- What is the difference between the EIGRP topology table, and the routing table
-EIGRP- In a network with dual redundant paths, how could you use an offset list
-What is the (TCP) 3-way handshake?
-How do you set up an OSPF network?
-You want to add an attached network into your OSPF configuration. What are the command(s)?
-What is redistribution in terms of routing protocols? What is mutual redistribution?
-What would be some problems with mutual redistribution?
-The LEC can't loop the CSU or NIU on a T1 circuit. Should you get the Cisco WIC replaced?

OSI Model
-In OSI terms, briefly describe what happens when you enter "www.google.com" in your
browser address bar, and hit enter
-Name the 7 layers
-What layer is TCP?
-What layer does a proxy server operate at?
-Describe the process by which one layer communicates with the next

Subnetting
-Usable hosts in a /23?
-How many bits for hosts are there in a /27?
-What's the dotted decimal equivalent of a /28?


DNS
-How do you look up a MX record?
-What is a CNAME?
-What is an A record?

Other
-How can you view routing information in a Unix server?
-How can you configure a static route in a Unix server?
-What is the command to list your current directory in Unix?
-Give an example of a regular expression used with the "|" character, in Cisco, or Unix
-Trick question--If you change the "bandwidth" on a router interface, and the interface utilization drops,
what could be an explanation?
-Have you used Wireshark?
-If I give you a Ethernet cable and pair of scissors can you make me a DS-1 loop back plug ....?
-Stateful firewall vs. access-lists vs. proxy server - how are they different?
-How do you show the arp table on a linux box? On a windows box? On a Cisco router?
-Briefly explain the difference between static and dynamic NAT
-Briefly explain the use of a virtual IP address in HSRP or VRRP