Jncia-Junos

Front 1

What does CTRL+U do in the CLI?

Back 1

Deletes all characters and negates the current command.

Front 2

What do you press on the keyboard to complete a command or option that you have partially typed?

Back 2

Spacebar

Front 3

What does CTRL+B do in the CLI?

Back 3

Moves the cursor left one character.

Front 4

This command displays summary information for the referenced configuration statement. It displays a complete list of related configuration options along with several other details specific to the command statement.

Back 4

help reference ?

Front 5

What does ESC+D do in the CLI?

Back 5

Deletes the word to the right

Front 6

Is command completion turned on or off by default in Junos OS?

What command do you use to enable and disable command completion?

Back 6

It is turned on by default.

To turn it off or on, type:
set cli complete-on-space off/on

Front 7

What EMACS-keyboard sequence moves the cursor forward one word with no delete?

Back 7

ESC+F

Front 8

This command displays the contexts (typically set commands) that reference a specific variable.

Note: It only displays contexts that are relevant to the configuration hierarchy level at which you are currently positioned.

Back 8

help apropos ?

Front 9

What EMACS-keyboard sequence deletes the character over the cursor?

Back 9

CTRL+D

Front 10

This command displays general usage guidelines for the statement.

Back 10

help topic ?

Front 11

What key do you use to complete system commands and user-defined variables?

Back 11

Tab key

Front 12

What does CTRL+W do in the CLI?

Back 12

Deletes the entire word to the left of the cursor.

Front 13

What does CTRL+A do in the CLI?

Back 13

Moves the cursor to the beginning of the command line.

Front 14

What does CTRL+F do in the CLI?

Back 14

Moves the cursor to the right one character.

Front 15

What EMACS-keyboard sequence deletes from the cursor to the end of the line?

Back 15

CTRL+K

Front 16

What EMACS-keyboard sequence redraws the current line?

Back 16

CTRL+L

Front 17

What EMACS-keyboard sequence repeats the previous and next command in the command history, respectively.

Back 17

Ctrl+P for previous
CTRL+N for next

Front 18

What does ESC+B do in the CLI?

Back 18

Moves the cursor back one word with no delete

Front 19

The Junos OS defaults to what terminal type?

Back 19

VT100

Front 20

What pipe option is available only in config mode using the show command that compares configuration changes with another configuration file?

Back 20

compare (filename | rollback #)

Front 21

What pipe option displays the number of lines in the output?

Back 21

count

Front 22

What pipe option tags changes with junos:changed attribute only for XML use?

(Only available in configuration mode)

Back 22

display changed

Front 23

What pipe option shows data after the Junos OS applies commit scripts?

Back 23

display commit-scripts

Front 24

What pipe option displays additional information about the contents of the configuration?

(Available in config mode only)

Back 24

display detail

Front 25

What pipe option displays inherited config data and source group?

(Available in config mode only)

Back 25

display inheritance

Front 26

What pipe option omits configuration statements with the omit option?

(Available in configuration mode only)

Back 26

display omit

Front 27

What pipe option shows set commands that created configuration statements?

(Available in configuration mode only)

Back 27

display set

Front 28

What pipe option displays the output in NETCONF/XML format?

Back 28

display xml

Front 29

What pipe option ignores text matching a regular expression when searching the output?

(If the regular expression contains spaces, operators, or wildcard characters, you must enclose it in quotation marks)

Back 29

except 'regular-expression'

Front 30

What pipe option displays the output starting at the first occurrence of text matching a regular expression?

(If the regular expression contains spaces, operators, or wildcard characters, you must enclose it in quotation marks)

Back 30

find 'regular-expression'

Front 31

What pipe option holds text without exiting --(more)-- prompt?

Back 31

hold

Front 32

What pipe option displays the last screen of information?

Back 32

last

Front 33

What pipe option searches for text matching a regular expression?

(If the regular expression contains spaces, operators, or wildcard characters, you must enclose it in quotation marks)

Back 33

match 'regular-expression'

Front 34

What pipe option displays output all at once rather than one screen at a time?

Back 34

no-more

Front 35

What pipe option displays output to multiple users?

Back 35

request message

Front 36

What pipe option converts IP addresses to DNS names?

Back 36

resolve

Also, it truncates to fit original size unless you specify full-names

Front 37

What pipe option saves the output to a file or URL?

Back 37

save 'filename'

Front 38

What pipe option trims specified number of columns from the start line?

Back 38

trim

Front 39

What command displays various types of information about the system and its environment?

Back 39

show

Front 40

What command allows you to issue operational mode commands while in configuration mode?

Back 40

run

Front 41

List the key operational mode capabilities (summary).

Back 41

- Entering configuration mode
- Controlling the CLI environment
- Exiting the CLI
- Monitoring and troubleshooting (clear, monitor, mtrace, ping, show, test, traceroute)
- Connecting to other network systems
- Copying files
- Restarting software processes
- Performing system-level operations

Front 42

What is the term for the currently operational configuration on the system and is the configuration that the system loads during the boot sequence?

Back 42

Active configuration

Front 43

What is the term for the temporary configuration that might possible become the active configuration?

Back 43

Candidate configuration

Front 44

What action causes the candidate configuration to become the active configuration?

Back 44

commit

Front 45

What command causes a candidate configuration to be created and populated with the contents of the active configuration?

Back 45

configure

Front 46

What is the command to recover previous configurations?

Back 46

rollback 'n' (n being the # of the rollback config)

Front 47

What is the maximum number of configurations that Junos OS saves?

Back 47

50

Front 48

What is the rollback number of the current active configuration?

Back 48

0 (rollback 0)

Front 49

What command do you enter to exclude other users from editing the configuration while you are doing so?

Back 49

configure exclusive

Front 50

True or false: by default, multiple users can enter configuration mode and commit changes?

Back 50

True

Front 51

What character is displayed that tells you that you are in operational mode?

Back 51

>

Front 52

What character is displayed that tells you that you are in configuration mode?

Back 52

#

Front 53

What command allows multiple users to edit the configuration while committing only their private changes?

Back 53

configure private

Front 54

In what deployment would the configure private command be automated?

Back 54

When chassis clustering is in effect.

Front 55

What command is used in the CLI to modify the candidate configuration?

Back 55

set

Front 56

What command is used to move down through an existing configuration statement hierarchy or to create a hierarchy and move down to that level?

Back 56

edit

Front 57

What command do you use to move up on level from the current position in the hierarchy?

Back 57

up

Front 58

What command moves you to the top of the configuration hierarchy?

Back 58

top

Front 59

What command returns the user to the most recent, higher level of the hierarchy.

Back 59

exit

Front 60

What command do you use to remove statements that you previously added to the configuration with the set command?

Back 60

delete

Front 61

What command can you use if you want to delete an entire hierarchy of configuration?

Back 61

wildcard delete

(example: wildcard delete interfaces ge-1/*)

Front 62

What command can you use to cause a specified portion of the configuration hierarchy to be ignored while still retaining the original configuration?

Back 62

deactivate

(activate to place back into effect)

Front 63

What command can you use to add a note to a configuration hierarchy, example: to explain why you made the change?

Back 63

annotate

(example: annotate name-server "added new name servers".)

Front 64

What command activates and synchronizes the configuration on both Routing Engines?

Back 64

commit synchronize

Front 65

How can you configure the system to automatically perform the synchronize option between Routing Engines when a standard commit is issued?

Back 65

set system commit synchronize

Front 66

What command validates the syntax of a candidate configuration without actually placing it into effect?

Back 66

commit check

Front 67

What command can you use to have the system start a timer, during which time it expects to see another commit, and if the commit does not occur within the time-out value it will automatically do a rollback 1, commit on your behalf to roll back?

Back 67

commit confirmed 'time-out'

Front 68

Other commit functionality includes:

Back 68

commit at 'time'
commit comment 'comment'
commit and-quit

Front 69

To view and clear pending commits, issue the following commands:

Back 69

show system commit
clear system commit

Front 70

What command can you use to compare the current active configuration to a saved configuration file?

Back 70

show configuration | compare 'filename'

Front 71

What command allows you to view differences between any two text files including log files?

(Command only available in operational mode)

Back 71

file compare files

Front 72

The default setting can be changed to increase the number of rollback files that are stored by the Junos OS. What is the command to change this?

Back 72

set max-configurations-on-flash 'number'

Front 73

What command can be used to load a complete or partial configuration from a local file, from a file on a remote machine, or from a terminal emulation program's capture buffer?

Back 73

load

Front 74

What load command argument replaces the full current configuration with the factory-default configuration?

Back 74

load factory-default

Front 75

What load command argument combines the current configuration with the configuration you load?

Back 75

load merge

Front 76

What load command argument completely overwrites the current configuration with the configuration you load?

Back 76

override

Front 77

What load command argument adds or deletes variables from the configuration based on the contents of a specified patch file?

Back 77

load patch

Front 78

What load command argument looks for a replace tag in the configuration file you load? The software then replaces existing statements of the same name with those in the loading configuration marked with the replace tag.

Back 78

load replace

Front 79

What load command argument allows users to load set commands from t he terminal or from a saved file that consists of set configuration arguments?

Back 79

load set

Front 80

What load command argument updates the existing configuration with the configuration you load?

Back 80

load update

Front 81

What load command argument uses the text you type at the terminal as input to the configuration? (This option is usually used in conjunction with a terminal emulation program's copy-and-paste functionality to copy/paste config data from one system to another)

Back 81

load terminal

Front 82

What load command argument negates the need to require the data to contain a full path to the related configuration hierarchy by telling the device to add the data you load relative to the current configuration hierarchy?

Back 82

load relative

Front 83

What two primary modes exist within the Junos OS?

Back 83

Operational & Configuration

Front 84

In Junos OS, each process runs on its own what?

Back 84

protected memory space

Front 85

What two planes exist in the Junos OS?

Back 85

Control and Forwarding

Front 86

What does the control plane run on?

Back 86

The routing engine

Front 87

What provides protocol updates and system management updates?

Back 87

Routing Engine

Front 88

What implements advanced services (such as rate limiting, stateless FW filters, and CoS?)

Back 88

The Packet Forwarding Engine (PFE)

Front 89

The forwarding plane runs on what?

Back 89

The PFE

Front 90

What maintains routing tables, bridging table, and the primary forwarding table in Junos ?

Back 90

The Routing Engine

Front 91

The routing engine connects to the packet forwarding engine through what?

Back 91

an internal link

Front 92

Define transit traffic.

Back 92

Traffic that enters the ingress interface, matches the routing table in the PFE, and is forwarded out the egress interface without ever being seen by the RE.

Front 93

Define exception traffic.

Back 93

Traffic that requires special handling by the RE.

Examples include:
Packets addressed to chassis, such as routing protocol updates, telnet sessions, pings, traceroutes, and replies to traffic sourced from the RE.

IP packets with the IP options field.

Traffic that requires generation of ICMP messages.

Front 94

What series of Juniper products running Junos OS supports 320 GB throughput, half-duplex?

It can be deployed in both high-end enterprise and service-provider environments. Deployed as gateway router, WAN connectivity router, campus core router, backbone, or data center routers.. etc

Back 94

M Series

Front 95

What series of Juniper products running Junos OS supports 2 GB throughput and is normally deployed at branch and remote locations?

Back 95

J Series

Front 96

What series of Juniper products running Junos OS supports 960 GB throughput, half-duplex, targeted for dense dedicated access aggregation and provider edge services in medium and large point of presence (POPs).

Back 96

MX Series

Front 97

What series of Juniper products running Junos OS supports 6.2 TBPS of full duplex throughput and are designed for low-density to high-density enterprise and data center environments?

Back 97

EX Series

Front 98

What series of Juniper products running Junos OS supports 120 GB of full duplex traffic and is deigned to meet network and security requirements for data centers, etc?

Back 98

SRX Series

Front 99

What series of Juniper products running Junos OS provides up to 25.6 Tbps of throughput and is ideal for service provider environments and is deployed within the core of those networks?

Back 99

T Series

Front 100

List all of the platform families that run the Junos OS:

Back 100

M Series, T Series, J Series, MX Series, EX Series, SRX Series

Front 101

What is required before activating any changes to the configuration file?

Back 101

Setting a root password

Front 102

EX Series switches are designed to operate how right out of the box?

Back 102

Layer 2: The factory-default config has all interfaces configured for L2 operation and also includes protocol config commonly used on switch, such as RSTP and LLDP

Front 103

What command allows you to overwrite the candidate configuration while in configuration mode?

Back 103

load factory-default

Front 104

For Junos devices that offer redundant Routing Engines, you can halt both REs simultaneously using what commnad?

Back 104

request system halt both-routing-engines

Front 105

For EX series switches participating in a virtual chassis, where multiple switches function as a single virtual device, you can halt all participating members simultaneously with what command?

Back 105

request system halt all-members

Front 106

What are the Junos OS password restrictions?

Back 106

All passwords are required to be no less than six characters and must include a change of case, digits, or punctuation.

Front 107

You can see the encrypted password by viewing what configuration?

Back 107

edit system
show root-authentication

Front 108

What is the default time zone on Junos devices?

Back 108

UTC

Front 109

By default, an individual CLI session times out when?

Back 109

By default, it never times out after extended timeouts.

Front 110

What is the command to set the CLI idle timeout?

Back 110

set cli idle-timeout #

(0 is disabled)

Front 111

What is the command to display a login message?

Back 111

set login message "message"

Front 112

What option marks a route ineligible for re advertisement through routing policy?

Back 112

no-readvertise

Front 113

What is the routing protocol process in Junos OS?

Back 113

rpd

Front 114

To allow the Junos device to boot and to ensure that it is reachable over the network if the routing protocol process fails to start properly, you can configure what?

Back 114

A backup router

(show backup-router)

Front 115

A ________ is a user-defined, known-good configuration that is designed to restore connectivity in the event of configuration problems.

Back 115

A rescue configuration.

By default, no rescue config is defined.

Front 116

What is the command to save the active configuration as the rescue configuration?

Back 116

request system configuration rescue save

Front 117

What command loads the rescue configuration?

Back 117

rollback rescue

Front 118

fxp0 and me0 are examples of what in some Junos platforms?

Back 118

Management interfaces

Front 119

fxp1 and em0 are examples of what in some Junos platforms?

Back 119

Internal interfaces

Front 120

What is the service interface name 'es' for?

Back 120

Encryption interface

Front 121

What is the service interface name 'gr' for?

Back 121

Generic route encapsulation tunnel interface

Front 122

What is the service interface name 'ip' for?

Back 122

IP-over-IP encapsulation tunnel interface

Front 123

What is the service interface name 'ls' for?

Back 123

Link services interface

Front 124

What is the service interface name 'ml' for?

Back 124

Multilink interface

Front 125

What is the service interface name "mo" for?

Back 125

Passive monitoring interface

Front 126

What is the service interface name 'mt' for?

Back 126

Multicast tunnel interface

Front 127

What is the service interface name 'sp' for?

Back 127

Adaptive services interface

Front 128

What is the service interface name 'vt' for?

Back 128

Virtual loopback tunnel interface

Front 129

What is the interface 'as' for?

Back 129

Aggregated SONET interface

Front 130

What is the interface 'ae' for?

Back 130

Aggregated ethernet interface

Front 131

Define unit number and define circuit identifier.

Back 131

The CI identifies the logical tunnel or circuit, and the unit number is used to identify a logical partition of the physical interface.

Although not required, it is recommended to keep the unit number and CI the same to aid in troubleshooting.

Front 132

If you issue a second 'set' command when an IP address on a single logical interface is already defined, what happens?

Back 132

It adds an additional address under the logical unit.

Front 133

Does the Junos OS form IGP adjacencies over all subnets when IGP is configured on a logical interface or does it form an adjacency over only the primary address of an interface?

Back 133

It forms them over all subnets - some vendors form an adjacency over only the primary address.

Front 134

Provide some physical interface property examples:

Back 134

- Data link layer protocol & Keep alives
- Link mode (duplex)
- Speed
- MTU
- Clocking (int clock source)
- Scrambling (payload scrambling on/off)
- FCS (frame check sequence - default is 16 bit mode)
- Diagnostic characteristics - enable local or remote loopbacks

Front 135

Provide some logical interface property examples:

Back 135

- Protocol family (inet, inet6, iso, mpls, ethernet-switching)
- Addresses (ip address)
- Virtual circuits (VCI, DLCI, VPI, or VLAN tag)

Front 136

True/False: The Junos OS considers all properties defined directly under the interface name to be physical properties of that interface, and all properties defined under the unit number to be logical properties of each particular subinterface.

Back 136

True

Front 137

When defining IP address, what does the preferred option do?

Back 137

If you have multiple IP addresses belonging to the same subnet on the same interface, this option allows you to select which address will be used as the source address for directly connected subnets. By default, the numerically lowest local address is chosen.

Front 138

To quickly verify the state of an interface you can issue what command?

Back 138

show interfaces terse

Front 139

Which configuration parameter is required during an initial configuration?

Back 139

root authentication

Front 140

List the password restrictions for Junos OS:

Back 140

- Must be at least 6 characters
- Can include most character classes in a password (alphabetic, numeric, and special characters)
- Cannot include control characters
- Passwords must contain at least one change of case or character class

Front 141

When a user is configured on a device running the Junos OS, the system automatically generates what for that user?

Back 141

A home directory

Front 142

A user's working directory (home directory) can be changed for individual sessions using what command?

(Operational mode command)

Back 142

set cli directory 'directory'

Front 143

Define authentication order in the Junos OS.

Back 143

For each login attempt, the Junos OS tries the authentication methods in order, until the password is accepted.

The next method in the authentication order is consulted if the previous authentication method failed to reply or if the method rejected the login attempt.

Front 144

Define "class" in the authorization overview and what are the four predefined login classes?

Back 144

Named container that groups together permission flags. You can configure custom ones, but there are four predefined login classes that exist.

* super-user (all permissions)
* operation (clear, network, reset, trace, and view)
* read-only (view permissions)
* unauthorized (no permissions)

Front 145

What commands can you use to explicitly deny or allow certain commands / configurations for user access?

Back 145

deny-commands, allow-commands, deny-configuration, allow-configuration

Front 146

The primary syslog file, which is included in all factory-default configuration, is the:

Back 146

/var/log/messages file

Front 147

What two hierarchies can syslog operations be enabled / modified at?

Back 147

edit system syslog

edit routing-options options syslog

Front 148

What syslog option displays the class of log messages?

Back 148

facility

Front 149

Standard log entries consist of what fields?

Back 149

Time stamp, name, process name or PID, message-code (purpose of the message), message-text (additional info related to the message code)

Front 150

What syslog configuration option causes the Junos OS to alter syslog message format to include numeric priority value? (0 indicates most significant, 7 indicates debug-level)

Back 150

explicit-priority

Front 151

_______ is the Junos term that other vendors sometimes call debugging.

Back 151

Tracing

Front 152

Trace the operations of a specific protocol by including ____ statement at the [edit protocols protocol-name] hierarchy:

Back 152

traceoptions

Front 153

List the configuration options for tracing files:

Back 153

* file 'filename'
* size 'size'
* files 'number' (max number of trace files, when a trace file reaches its max size, it is renamed to tracefile.0 and a new tracefile is created)
* no-stamp (prevents time stamp info)
* replace (replaces existing trace file if one exists)
* readable (allows any user to view file)
* no-world-readable (allows only the user who configured the file to view it - this is the default setting)

Front 154

What file by default is used for global interface tracing?

Back 154

/var/log/dcd

Front 155

By default, the Junos OS stores log and trace files in:

Back 155

/var/log

Front 156

To view stored log files, use the __ command:

Back 156

show log

Front 157

To view real time log information, use the ____ command:

Back 157

monitor start

Front 158

To determine which log files are being monitored, you can issue what command?

Back 158

monitor list

Front 159

What keyboard sequence is used to enable or disable syslog output to the screen?

Back 159

Esc+q

Front 160

To disable all tracing at a particular hierarchy, issue what command at that hierarchy?

Back 160

delete traceoptions

Front 161

To truncate files used for logging, use what command?

Back 161

clear log 'filename'

Front 162

What modes of NTP operation does the Junos OS support?

Back 162

client, server, and symmetric. also can support broadcast and authentication.

Front 163

By default, if the time difference between the local device's clock and the NTP server's clock is more than ___________, the clocks are slowly stepped into synchronization.

Back 163

128 ms

Front 164

What happens if the local device's clock is mroe than 1000 seconds different than the NTP server's clock?

Back 164

The clocks are not synchronized

Front 165

What command is used to display synchronization status for NTP?

Back 165

show ntp associations or show ntp status

Front 166

At what hierarchy can you configure sending automatic system backups to a remote device?

Back 166

edit system archival

Front 167

Backups occur at regular intervals with the use of what statement?

Back 167

transfer-interval

Front 168

The config file can be transferred to a remote device every time a new config becomes active with the use of what statement?

Back 168

transfer-on-commit

Front 169

When the system goes to copy the configuration file to a remote device, in what directory does it first copy the file to on the system?

Back 169

/var/transfer/config

Front 170

Junos OS provides support for what SNMP versions?

Back 170

1, 2C, and 3

Front 171

You can obtain most system information using what command?

Back 171

show system 'argument'

Front 172

This show system argument displays current system alarms?

Back 172

show system 'alarms'

Front 173

This show system argument displays the message seen during the last system boot?

Back 173

show system 'boot-messages'

Front 174

What does the show system 'connections' argument display?

Back 174

the status of local TCP and UDP connections

Front 175

What does the show system 'statistics' argument display?

Back 175

provides options for viewing various protocol statistics

Front 176

This show system argument displays the status of the file system storage space?

Back 176

show system 'storage'

Front 177

You can monitor the chassis and obtain chassis information using what command?

Back 177

show chassis 'argument'

Front 178

What does the show chassis 'alarms' argument display?

Back 178

current chassis alarms

Front 179

What does the show chassis 'environment' argument display?

Back 179

displays component and environmental status as well as the operational speeds of the cooling system

Front 180

What show chassis argument displays an inventory of the installed hardware components along with the SN# of each component?

Back 180

show chassis hardware

Front 181

What show chassis argument provides operational status and utilization details for the RE?

Back 181

show chassis routing-engine

Front 182

What command is used to view detailed information for a named interface?

Back 182

show interface extensive

Front 183

If you do not specify an interface when running the monitor traffic command, what interface is monitored by default?

Back 183

management interface

Front 184

What monitor traffic option allows you to save packet captures for analysis with a third party packet decoder?

Back 184

write-file

Front 185

What command allows you to transfer files to and from devices running the Junos OS?

Back 185

file copy

Front 186

What command allows you to determine the current Junos OS release on a device?

Back 186

show version

Front 187

Describe the jkernel Junos package:

Back 187

The kernel and network tools package, contains basic operating system files.

Front 188

Describe the jroute Junos package:

Back 188

This package contains the RE software.

Front 189

Describe the jpfe package:

Back 189

The PFE package, contains the PFE software.

Front 190

Describe the jdocs package:

Back 190

Documentation package, contains documentation set for the software.

Front 191

Describe the jcrypto package:

Back 191

The encryption package. Contains domestic version of the security software.

Front 192

What is the Junos naming convention form

Back 192

package-release-edition

Front 193

What is the command to upgrade the Junos OS?

Back 193

request system software add 'path/image name'

Front 194

Where should Junos OS images be stored in preparation for an upgrade?

Back 194

/var/tmp

Front 195

You can delete Junos images stored in the /var/tmp/ directory when you perform the file system cleanup operation using what command?

Back 195

request system storage cleanup

Front 196

What enables you to upgrade between two different Junos OS releases with no disruption on the control plan and with minimal disruption of traffic?

Back 196

A Unified In-Service Software Upgrade (unified ISSU)

Front 197

Unified ISSU is only supported on what?

Back 197

Dual Routing Engine Platforms

Front 198

What must be enabled to do a unified ISSU?

Back 198

Graceful routing engine switchover (GREs) and nonstop active routing (NSR)

Front 199

True / False: The master RE and backup RE must be running the same software release before you can perform a unified ISSU.

Back 199

True

Front 200

What command do you use to perform a unified ISSU?

Back 200

request system software in-service-upgrade

Front 201

What are the steps for performing password recovery?

Back 201

1) Reboot the system
- Press spacebar when prompted
- Enter boot -s to access single user mode
2) Enter recovery when prompted to go into recovery mode
3) Set root password
4) Commit the change and exit configuration mode - reboot when prompted

Front 202

Which command do you use to view interface usage details in real time?

Back 202

monitor interface or monitor interface traffic

Front 203

Which command do you use to perform packet captures?

Back 203

monitor traffic interface

Front 204

What is the primary routing table in the Junos OS?

Back 204

inet.0 (stores IPv4 unicast routes)

Front 205

What is the Junos OS predefined routing table inet.1 used for?

Back 205

Multicast forwarding cache

Front 206

What is the Junos OS predefined routing table inet.2 used for?

Back 206

Multicast Border Gateway Protocol (MBGP) routes to provide reverse path forwarding (RPF) checks

Front 207

What is the Junos OS predefined routing table inet.3 used for?

Back 207

MPLS path information

Front 208

What is the Junos OS predefined routing table inet.4 used for?

Back 208

Used for multicast source discovery protocol (MSDP) route entries

Front 209

What is the Junos OS predefined routing table inet6.0 used for?

Back 209

IPv6 unicast routes

Front 210

What is the Junos OS predefined routing table mpls.0 used for?

Back 210

Used for MPLS next hops

Front 211

What is the default route preference for system routes 4?

Back 211

4

Front 212

What is the default route preference for static and static LSPs?

Back 212

5

Front 213

What is the default route preference for RSVP-signaled LSPs?

Back 213

7

Front 214

What is the default route preference for LDP-signaled LSPs?

Back 214

9

Front 215

What is the default route preference for OSPF internal?

Back 215

10

Front 216

What is the default route preference for IS-IS Level 1 internal?

Back 216

15

Front 217

What is the default route preference for level 2 internal?

Back 217

18

Front 218

What is the default route preference for redirects?

Back 218

30

Front 219

What is the default route preference for Kernel?

Back 219

40

Front 220

What is the default route preference for SNMP?

Back 220

50

Front 221

What is the default route preference for router discovery?

Back 221

55

Front 222

What is the default route preference for RIP?

Back 222

100

Front 223

What is the default route preference for RIPing?

Back 223

100

Front 224

What is the default route preference for DVMRP?

Back 224

110

Front 225

What is the default route preference for aggregate?

Back 225

130

Front 226

What is the default route preference for OSPF AS external?

Back 226

150

Front 227

What is the default route preference for ISIS-Level 1 EXTERNAL?

Back 227

160

Front 228

What is the default route preference for IS-IS Level 2 EXTERNAL?

Back 228

165

Front 229

What is the default route preference for BGP?

Back 229

170

Front 230

What is the default route preference for MSDP?

Back 230

175

Front 231

What does the rpd (routing protocol daemon) do if equal-cost paths exist for the same destination?

Back 231

Randomly selects one of the available paths

Front 232

What command is used to view the forwarding table contents?

Back 232

show route forwarding-table

Front 233

What does the default forwarding entry do?

Back 233

Matches all packets when no other matching entry exists. When a packet matches this default entry, the route discards the packet and it sends an ICMP destination unreachable msg.

Front 234

The Junos OS creates a default unicast routing instance called the ?

Back 234

Master routing instance (by default, includes inet.0)

Front 235

What is the user-defined routing instance 'forwarding' used for?

Back 235

Used to implement filter-based forwarding for common Access Layer applications

Front 236

What is the user-defined routing instance 'l2vpn' used for?

Back 236

Layer 2 vpn implementations

Front 237

What is the user-defined routing instance 'no-forwarding' used for?

Back 237

used to separate large networks into smaller administrative entities

Front 238

What is the user-defined routing instance 'virtual-router' used for?

Back 238

used for non-VPN related applications such as system virtualization

Front 239

What is the user-defined routing instance 'vpls' used for?

Back 239

used for point-to-multipoint LAN implementations between a set of sites in a VPN

Front 240

What is the user-defined routing instance 'vrf' used for?

Back 240

used in layer 3 vpn implementations

Front 241

Within the Junos OS, the way to represent the dropping of packets is with the keywords:

Back 241

reject or discard

Front 242

What are the differences between reject and discard?

Back 242

Reject send an ICMP unreachable message back to the source of the IP packet, discard does not send back an ICMP message (drops silently)

Front 243

What option allows independent preferences for static routes to the same destination?

Back 243

qualified-next-hop

Front 244

What are examples of IGPs?

Back 244

RIP, IS-IS, and OSPF

Front 245

What is an example of an EGP?

Back 245

BGP

Front 246

What type of routing protocol is OSPF?

Back 246

link state

Front 247

Devices running OSPF send out information about their network links and the state of those links to other routers in the AS. It transmits reliably to all other routes by means of what?

Back 247

LSAs (Link state advertisements)

Front 248

Three major tasks of OSPF:

Back 248

Flooding LSAs
Discovering neighbors
Establishing the LSDB (link state DB)

Front 249

What is a logical group of routers called in relation to OSPF?

Back 249

OSPF area

Front 250

Each OSPF router maintains a separate _______ for each area to which it is connected

Back 250

LSDB

Front 251

OSPF designates a special area (area 0.0.0.0) in which all other OSPF areas must connect themselves to for connectivity and all data traffic between OSPF areas must transit this. What is it called?

Back 251

backbone area

Front 252

List the possible OSPF states:

Back 252

Attempt, Down, Exchange, ExSTart, Full, Init, Loading, or 2 way

Front 253

By default, devices running the Junos OS system treat all transit traffic how?

Back 253

Equally; no CoS

Front 254

What algorithm do most devices running Junos OS use to avoid congesttion and how does it work?

Back 254

RED (Random Early Detection)

- Selectively drops random packets before congestion becomes critical. Causes the affected TCP sessions to go into slow-start mode, reducing the total amount of traffic clients attempt to transmit.

Front 255

You can configure devices running Junos to set the forwarding class and loss priority for a given packet based on the values of certain head fields, these include:

Back 255

DiffServ code point (DSCP), IP precedence, MPLS EXP, and IEEE 802.1p.

Front 256

You can configure devices running Junos to set the forwarding class and loss priority for a given packet based on the values of certain head fields. What are these values called?

Back 256

Behavior Aggregate classifiers

Front 257

What are the two primary CoS deployment models and how do they differ?

Back 257

In-the-box model: uses only a multifield classifier

Across-the-network model: uses a multifield classifier at edge and BA rewrite and classifier in the core

Front 258

You configure Junos devices to apply BA markers to packets leaving an interface by applying what on an outbound interface?

Back 258

rewrite rule

Front 259

Under what hierarchy do you apply rewrite rules?

Back 259

edit class-of-service interfaces

Front 260

For example, to apply the default IP precedence markings in relation to CoS, the command would be:

Back 260

set 'interface-name' unit 'logical-unit-number' rewrite-rules inet-precedence default

Front 261

You apply BA classifiers to interfaces under what hierarchy?

Back 261

edit class-of-service interfaces

Front 262

What do policers do?

Back 262

Allow you to limit certain kinds of traffic to a specified bandwidth and burst size.

Front 263

List the default queues for Junos CoS and forwarding class mappings?

Back 263

0 - Best Effort
1 - Expedited-Forwarding
2 - Assured-Forwarding
3 - Network-Control

Front 264

By default, the Junos os sends what type of traffic out of the network-control forwarding class?

Back 264

routing protocol msgs, keepalives, etc

Front 265

All other traffic, by default, is sent out what queue?

Back 265

Queue 0 (best effort)

Front 266

Define a scheduler and a scheduler map:

Back 266

A scheduler contains parameters that describe how to service a queue and is associated with a particular queue and forwarding class through a scheduler map.

Front 267

by default, the software assigns how much bandwidth to the queue associated with the best-effort forwarding class?

Back 267

95 percent

Front 268

By default, the software assigns how much bandwidth to the queue associated with network-control?

Back 268

5 percent

Front 269

The software assigns all queues besides network-control and best-effort what transmission rate and by default what can they do

Back 269

0 transmission rate; they can exceed their assigns transmission rate if other queues are not fully utilizing their assigned rates (unless you configure the transmission rate with the "exact" option)

Front 270

What hierarchy do you configure schedulers at

Back 270

edit class-of-service schedulers

Front 271

You can quickly see most of the CoS configuration for an interface using what command?

Back 271

show class-of-service interface 'interface'

Front 272

On most interfaces, you can see CoS summary statistics for each queue using what commands

Back 272

show interfaces detail or show interfaces extensive

Front 273

Explain the difference between a behavior aggregate classifier and a multifield classifier?

Back 273

Multifield classifier goes in a firewall filter and it can classify traffic based on any of the match conditions available in FW filters.

A BA classifier classifies traffic based on a specific behavior aggregate markings in packet headers.

You typically use mutilfield classifiers on the edge of the network to initially classify traffic, you typically use BA markings to maintain classification within the network.