DDevice COnfiguration

Question 1

What are the two types of configuration?

Answer 1

Active
Candidate

Question 2

Where does a candidate config come from?

Answer 2

It spawns when you enter configure mode. Created based on the current running config.

Question 3

How do you apply a candidate configuration?

Answer 3

Commit.

if it passes the syntax checks it gets moved to active.

Question 4

How many rollback configs are stored?

Answer 4

Active + 49 old (50)

Question 5

How many users can be in configure mode at the same time?

Answer 5

32

Question 6

Whats configure exclusive?

Answer 6

Enters you into configuration mode and stops, and blocks other users entering it until you’re done.

Question 7

Whats configure private?

Answer 7

Enables multi-user config with each user getting their own candidate config.

All other users must use config private

rollback 0 rolls back only that users candidate while private mode is active.

An admin can take over with configure exclusive.

Question 8

What happens when two users apply the same config in configure private?

Answer 8

First users commit is good.
Second user will get a commit error advising over-write coming. if they commit again it will use the second users config.

Question 9

what is config batch?

Answer 9

batch config mode. its for applying lots of small config changes in batches to be more efficient. Changes are queued up, and then the batch server applies them together.

Question 10

What is configure dynamic?

Answer 10

Its a lightweight config mode for creating routing policies and routing objects.

Commits faster.

Question 11

What does ; in the config mean?

Answer 11

Means the end of a leaf - nothing else in that specific context.

Question 12

how do you go up in the config heirarchy?

Answer 12

up
or to move up x levels;
up x

Question 13

How do you use top?

Answer 13

top takes you to the top of the hierarchy.

it can be chained with other commands to go up and then down another branch - eg;

top edit system login

Question 14

what does exit do?

Answer 14

takes you back to the previous level hierarchy you were in

If you’re already at the top exit takes you out of config mode back to operational

exit configuration mode also quits you back to op instantly.

Question 15

What does deactivate do?

Answer 15

Turns off a block of config without removing all of the config commands.

Question 16

What does activate do?

Answer 16

turns a block of config back on again

Question 17

command “set interface ge-0/0/0 disable” was commited. How do you undo it?

Answer 17

delete interfaces ge-0/0/0 disable

Question 18

how do you view the candidate config?

Answer 18

from config mode, show

You can use more specific commands like;

show system services

Question 19

how do you view the specific set commands in a config?

Answer 19

show system services | display set

Question 20

Where can you commit from?

Answer 20

Any level, unless you’re in commit private - and then you have to be at the top

Question 21

Commits on dual RE devices?

Answer 21

commit synchronize pushes the candidate to both REs

Question 22

How do you config auto commit synchronize?

Answer 22

set system commit synchronize

Question 23

what does commit check do?

Answer 23

syntax checks the candidate config without applying it

Question 24

what does commit confirmed do?

Answer 24

Commits the config and starts a 10 minute timer. At the end of the timer it reverts.

end the timer and confirm the commit with a second commit.

This prevents you locking yourself out of a device.

By default its 10 minutes. You can specify between 1 and 65,535 minutes.

Question 25

What does commit at <time> do?</time>

Answer 25

schedules a commit

View scheduled commits with

show system commit

cancel them with

clear system commit

Question 26

How do you compare the candidate to the active config?

Answer 26

from configure mode,

show | compare

Question 27

how do you know if you have a scheduled commit?

Answer 27

show system commit

look for “commit requested by <user> via cli at <datetime></datetime></user>

Question 28

how do you add a comment to a commit?

Answer 28

commit comment

Question 29

what does commit prepare do?

Answer 29

it creates a new version of the config, does syntax validation but doesnt make the config live yet.

commit activate completes the prepare.

Question 30

How do you compare active to a rollback config?

Answer 30

show configuration | compare rollback <number></number>

Question 31

how do you compare two text files?

Answer 31

file compare files <file1> <file2></file2></file1>

Question 32

how do you change the number of rollback configs that can be saved?

Answer 32

edit system
set max-configurations-on-flash <1-49>

Question 33

Whats the rescue config?

Answer 33

Allows you to define a known working config prior to making changes. Means you dont need to remember or track which rollback is good.

Can also be used as a last resort if the config/backup config gets lost.

Question 34

How do you make a rescue config?

Answer 34

Request system configuration rescue save

Question 35

how do you revert to the rescue config?

Answer 35

rollback rescue
commit

Question 36

What is the Ephemeral configuration database?

Answer 36

Alternate config DB for commiting config changes.

Accessed via JET/XML API - not CLI
Fast. can do 1,000’s of commits/min.
Does only basic syntax checks. You can commit config that references things that dont exist which will break stuff.

Question 37

What happens if the config databases during a commit conflict?

Answer 37

Ephemeral wins.