[nsp] bgp/ospf interview questions ?

[Pete Templin]

Sean Mathias wrote:
> As no questions/answers can ever (well rarely) show a person has
> practical knowledge, I eventually moved to mini-labs.  These were
> nothing heavy, open-book (cisco.com) and less than 90 minutes.  They
> progressed through basics such as configuring HSRP, trunks,
> etherchannel, to basic OSPF/EIGRP/BGP, then BGP filtering.  You can
> craft just about any scenario, to any degree of complexity relevant to
> the position you are hiring for.  Let them know before they come in that
> there will be a hands-on portion.  This weeds out those that it should,
> and takes away any surprises.  I let them work alone (without looking
> over their shoulders) and am available for questions.  This has proved
> very successful for me in my hiring.

Here's excerpts of a test I recently put together:

This quiz is designed to allow you to demonstrate your operational 
knowledge of Cisco routers and configuring IOS.  There will be three 
levels to the quiz. You may complete any or all of the three levels of 
the quiz, based on your comfort with the questions asked.

For all three levels of the quiz, you will be configuring Router1.  You 
can connect to Router1 through either the console port (via 
HyperTerminal) or by telnet to the address 172.16.3.126.  Any router 
passwords needed on Router1 are “cisco”.

Router2 is completely pre-configured for this quiz, and you should not 
need to make any changes on Router2 at any point.  If you feel that 
there may be a hardware problem with Router2, please let the interviewer 
know ASAP.



Level 1: Static routing

Task: Configure Router1 to allow the laptop to access the web server 
located at the IP address 172.16.0.34 over either T1 connection.  All 
interface IP addresses have been configured to match the attached 
network diagram, and Router2 is properly configured for the connection.

Outcome: When you are complete, you should save your work so the router 
could be rebooted and continue to work.  You should also visit the web 
server listed above, and let the interviewer know the “magic word” shown 
on the website.

Bonus topics:

1)	Configure the router to use both T1s.  You should be able to shut 
down either T1 interface and still reach the web server.
2)	(Advanced) Configure the router to use both T1s with per-packet load 
balancing, so that you can upload a file to the server at 3Mbps.



Level 2: OSPF routing

Task: Configure Router1 to allow the laptop to access the web server 
located at the IP address 172.16.0.34 over either T1 connection.  All 
interface IP addresses have been configured to match the attached 
network diagram, and Router2 is properly configured for the connection. 
  Use OSPF routing in area 0 to learn the routes for the rest of the 
network.

Outcome: When you are complete, you should save your work so the router 
could be rebooted and continue to work.  You should also visit the web 
server listed above, and let the interviewer know the “magic word” shown 
on the website.

Bonus topics:

1)	Configure the router to use both T1s.  You should be able to shut 
down either T1 interface and still reach the web server.  You may need 
to wait a short period for the routes to converge.
2)	Configure the static routes from the first section of the quiz to be 
backup routes, so the OSPF routes show up in the routing table of 
Router1 unless OSPF should become broken on Router2.
3)	(Advanced) Configure the router to use both T1s with per-packet load 
balancing, so that you can download a file from the web server at 3Mbps.



Level 3: BGP routing

Task: Configure Router1 to allow the laptop to access the web server 
located at the IP address 172.16.0.34 over either T1 connection.  All 
interface IP addresses have been configured to match the attached 
network diagram, and Router2 is properly configured for the connection. 
  Use BGP routing to learn the routes for the rest of the network.  Your 
local AS is 65101, and router 2’s AS is 65102.  Also, announce the local 
area network, 172.16.3.0/25, to Router2.

Outcome: When you are complete, you should save your work so the router 
could be rebooted and continue to work.  You should also visit the web 
server listed above, and let the interviewer know the “magic word” shown 
on the website.

Bonus topics:

1)	Configure Router1 to tell Router2 to not pass the routes learned from 
Router1 to any other BGP networks.
2)	Configure Router1 to tell Router2 to send traffic destined for 
172.16.3.0/25 (the local area network on Router1) over Serial0/0 if both 
T1s are up.

Other information (Visio diagram, etc.) available by off-list request.

pt