Free Practice Questions for RUCKUS RCNI Exam

Comparison Between supportsave and show tech-support:

show tech-support: Generates diagnostic information and displays it on the CLI. It does not directly save or transfer the output.

supportsave: Gathers similar diagnostic data but also allows the data to be transferred to a remote server, such as via TFTP, for easier analysis.

Why Other Options Don't Apply:

A. Uses fewer CPU cycles during execution: Both commands are similar in terms of resource usage.

C. Uploads directly to RUCKUS support: Data transfer to RUCKUS support requires manual intervention.

D. Generates automatically after a system crash: Neither command generates data automatically; both require user execution.

References:

ICX Switch SupportSave Command Guide: RUCKUS Documentation

To enable Open Shortest Path First (OSPF) globally on a RUCKUS ICX switch, the router ospf command is used. This command initiates OSPF routing processes, allowing the switch to participate in OSPF-based dynamic routing.

Steps to Enable OSPF Globally:

Access Global Configuration Mode:

Enter privileged EXEC mode and then global configuration mode:

enable

configure terminal

Enable OSPF Routing:

Activate the OSPF routing process:

router ospf

Assign OSPF Parameters:

Set the router ID (optional but recommended):

router-id

Specify OSPF areas and associate interfaces:

network area

Configure OSPF on Interfaces:

Enter interface configuration mode for each interface participating in OSPF:

interface

ip ospf area

Save Configuration:

Ensure the configuration persists after a reboot:

write memory

Example Configuration:

To configure OSPF with a router ID of 1.1.1.1 and include the network 192.168.1.0/24 in area 0:

configure terminal

router ospf

router-id 1.1.1.1

network 192.168.1.0 0.0.0.255 area 0

exit

interface ethernet 1/1/1

ip ospf area 0

exit

write memory

Considerations:

Licensing: Ensure the switch has the appropriate Layer 3 license to support OSPF.

Compatibility: Verify that the FastIron software version supports OSPF.

Network Planning: Properly design OSPF areas and hierarchies to optimize routing efficiency.

References:

Ruckus FastIron Layer 3 Routing Configuration Guide, 08.0.91

Ruckus FastIron Command Reference Guide, 08.0.70

Class of Service (CoS) and Differentiated Services Code Point (DSCP) are both mechanisms used to prioritize network traffic, but they function at different layers of the OSI model and have distinct characteristics:

Operational Layer:

CoS:

Operates at Layer 2 (Data Link Layer) of the OSI model.

Utilizes a 3-bit field within the 802.1Q VLAN tag, known as the Priority Code Point (PCP), to assign priority levels ranging from 0 to 7.

DSCP:

Operates at Layer 3 (Network Layer) of the OSI model.

Uses a 6-bit field in the IP header to assign priority, allowing for up to 64 different values, providing more granularity in traffic classification.

Scalability and Complexity:

CoS:

With only 8 possible priority levels, CoS offers limited granularity.

As network demands increase, especially with diverse applications requiring different levels of service, managing and differentiating traffic with CoS can become complex due to its limited priority levels.

DSCP:

Provides 64 distinct priority levels, allowing for finer differentiation of traffic types.

This granularity enables easier scalability and more straightforward management of diverse and growing network traffic demands.

References:

For a detailed comparison between CoS and DSCP, refer to the NetworkLessons Notes on QoS CoS vs DSCP: QoS CoS vs DSCP - NetworkLessons Notes

For an overview of Differentiated Services and traffic classification, see the article on GeeksforGeeks: Differentiated Services (DiffServ) and Traffic Classification

Understanding these differences is crucial for network administrators when designing Quality of Service (QoS) policies to ensure efficient and effective traffic management across the network.

In RUCKUS ICX switches, VLAN 1 is the default VLAN and is typically used for management purposes. By default, all ports are members of VLAN 1 as untagged. Attempting to configure VLAN 1 as tagged on a port can result in an error, as the system restricts tagging the default VLAN.

Understanding the Error:

RKUS-01(config)# vlan 1

RKUS-01(config-vlan-1)# tagged ethernet 1/2/1

Invalid input -> tagged ethernet 1/2/1

Type ? for a list

This error occurs because the switch does not allow tagging of the default VLAN (VLAN 1) on any interface.

Resolution:

Option 1: Use a Different VLAN for Tagging

Create a new VLAN (e.g., VLAN 2) and configure it as tagged on the desired port.

RKUS-01(config)# vlan 2

RKUS-01(config-vlan-2)# tagged ethernet 1/2/1

Option 2: Change the Default VLAN ID

If you must use VLAN 1 as tagged, you can change the default VLAN ID to another VLAN (e.g., VLAN 2), allowing VLAN 1 to be configured as tagged.

RKUS-01(config)# default-vlan-id 2

RKUS-01(config)# vlan 1

RKUS-01(config-vlan-1)# tagged ethernet 1/2/1

Open Shortest Path First (OSPF) is a widely used interior gateway protocol (IGP) designed for routing within an autonomous system (AS). It is a link-state routing protocol that offers several key features:

Key Features of OSPF:

Calculates Link Cost:

OSPF assigns a cost to each link, representing the overhead required to send packets across that link. The cost is typically based on the link's bandwidth; higher bandwidth links have lower costs.

OSPF uses these costs to calculate the shortest path to each network destination, ensuring efficient routing.

Updates Routes Dynamically:

OSPF routers exchange link-state advertisements (LSAs) to share information about network topology changes.

When a change occurs, such as a link failure, OSPF quickly propagates this information, allowing routers to update their routing tables dynamically and converge on a new optimal topology.

Clarifications on Other Options:

Option A: Utilizes distance vector

OSPF is a link-state protocol, not a distance vector protocol. Distance vector protocols, like RIP, use different mechanisms for route calculation.

Option C: Automatic redistribution of routes

OSPF does not automatically redistribute routes from other routing protocols. Route redistribution between different protocols requires manual configuration.

Option E: Uses exterior gateway protocols

OSPF is an interior gateway protocol (IGP) used within a single autonomous system, not an exterior gateway protocol (EGP) like BGP, which is used between autonomous systems.

References:

OSPF Design Guide

Understanding OSPF

In Virtual Router Redundancy Protocol Extended (VRRP-E) configurations on RUCKUS ICX switches, the master router sends hello messages at regular intervals to indicate its active status. By default, these hello messages are sent every 1 second.

Key Points:

Hello Interval: The frequency at which the master router sends hello messages to backup routers.

Default Value: 1 second.

Purpose: To inform backup routers of the master's presence and operational status. If backup routers do not receive hello messages within a specified dead interval, they assume the master is down and initiate a failover.

Configuration:

Viewing Current Settings:

To display the current VRRP-E configuration, including hello intervals:

sql

Copy code

show vrrp

Modifying the Hello Interval:

To change the hello interval, enter VRRP-E configuration mode for the specific virtual router instance and use the following command:

php

Copy code

vrrp advertisement-interval

: Virtual Router ID.

: Desired interval in seconds.

Example:

To set the hello interval to 2 seconds for VRID 1:

bash

Copy code

enable

configure terminal

interface ethernet 1/1/1

vrrp 1

advertisement-interval 2

exit

write memory

Considerations:

Network Stability: Setting the hello interval too low can lead to unnecessary failovers due to transient network issues. Conversely, setting it too high can delay failover detection.

Consistency: Ensure that all routers in the VRRP-E group have consistent hello and dead interval settings to prevent configuration mismatches.

References:

Ruckus FastIron Layer 3 Routing Configuration Guide, 08.0.91

Ruckus FastIron Command Reference Guide, 08.0.70

When a high CPU utilization alert is triggered on a RUCKUS ICX switch, it's essential to identify the processes consuming excessive CPU resources. The show cpu tasks command provides detailed information about active processes and their CPU usage.

Command Usage:

show cpu tasks

Output Example:

Task Name CPU Time (ms) Invocations Avg Time (us)

------------------ -------------- ------------ -------------

TaskA 5000 1000 5000

TaskB 3000 1500 2000

In this output:

Task Name lists the names of active processes.

CPU Time (ms) indicates the total CPU time consumed by each process in milliseconds.

Invocations shows how many times each process has been called.

Avg Time (us) represents the average time per invocation in microseconds.

By analyzing this data, administrators can pinpoint processes that are utilizing disproportionate CPU resources, facilitating targeted troubleshooting and optimization.

In RUCKUS ICX switches, certain VLAN IDs are reserved for system functions and cannot be used for user-defined VLANs. Specifically, the following VLAN IDs are reserved:

VLAN 0: Reserved for priority tagging.

VLAN 1: Default VLAN for untagged frames.

VLAN 4095: Reserved and cannot be used.

VLAN 4094: Reserved and cannot be used.

VLAN 4093: Reserved and cannot be used.

This totals to 5 reserved VLAN IDs.

These reservations are standard across many networking devices to ensure proper network operations and to avoid conflicts with system-level processes. It's important to note that while VLAN 1 is the default VLAN, it can be reassigned if necessary, but caution should be exercised to avoid disrupting network management and control traffic.

For detailed information on VLAN configuration and reserved VLAN IDs on RUCKUS ICX switches, please refer to the RUCKUS FastIron Layer 2 Switching Configuration Guide:

FastIron Layer 2 Switching Configuration Guide

This guide provides comprehensive information on VLAN management, including details on reserved VLAN IDs and best practices for VLAN configuration on RUCKUS ICX switches.