Tag: switch

Passing my CCNP Switch 300-115 Exam

by Samuel Mitchell, posted in Routing & Switching

I am on a journey to certify my networking experience after years in the field by targeting the CCNP Routing & Switching certification. It is a challenging and tedious journey especially with information relating to some aspect of routing or switching which is not usually known and you will just research it on Google.

After acquiring my CCNA R&S in 2009, I decided to take a break. I ended up waiting until the certification almost expired in 2012 when I attempted the CCNA R&S composite exam on the last day in an effort to renew it but I failed miserable (which I totally regret). The expired status forced me to redo the entire CCNA R&S track ICND1 and ICND2.

I was advised not to do the composite exam because it is skills against time which will put me under pressure. I took the advise and did the exams in two parts and I was successful within one year.

With the enthusiasm after passing and achieving my CCNA R&S certification, I started on the CCNP track by tackling the CCNP R&S Switch first. After 1 month of studying and with the CCNA knowledge fresh in my mind, I took the exam and failed by a few points off. Man, this was heart rending. I decide No, this is not going to deter me. I went back after two months and did it again. Wow, the same result. This journey continued for seven (7) attempts and final I passed the exam with flying colors on November 8, 2019.

After reviewing the topics and objectives of the CCNP R&S switch 300-115 exam and seven (7) times exam experience, I formulated the following recommendations for preparing for the CCNP R&S Switch 300-115 which can apply to any Cisco exam:

  1. Know the protocol inner workings.
  2. Know the compatibility of more than one protocols working together e.g. Private-VLAN with SPAN or STP with Protected Port.
  3. Know the scenarios or cases that the features will best fit. for example Private-VLAN is good for using one IP address subnet and separating customers from each other like in an ISP case.
  4. Pay attention to the percentage or weight of each topics or sections on the blueprint and focus more on those features.
  5. Read the Cisco documentation for in dept information of each feature that is missing from other resources. this information will also help with cases or scenarios application.
  6.  Lab and practice with real gears: my recommendation:
    1. Cisco 3750: for stacking
    2. Cisco 3560 : private vlans, SVI
    3. Cisco 2960: PVLAN not supported and SVI
  7. Practice test (measureup is good)
  8. Set your Exam Date and workout a schedule from that date and stick to it.
  9. Create a Study Schedule of each topic on the exam blueprint

The resources I used to prepare:

  1. Cisco CCNP SWITCH 300-115 Hands-on Labs Exam Prep  (CBTNUggets)
  2. Cisco CCNP Routing and Switching 300-115 SWITCH
  3. CCNP Switching (300-115) Cert Prep: 1 Layer 2 Technologies – Linked Learning
  4. CCNP Switching (300-115) Cert Prep: 2 Infrastructure Security and Services – Linked Learning
  5. Cisco 3750 switch configuration guide (from Cisco docs)
  6. CCNP Routing and Switching SWITCH 300-115 Official Cert Guide (Pearson IT Certification)

I have  study notes that I will share in the coming weeks for those who are preparing for CCNP R&S Switch 300-115 exam. Although Cisco is changing their exams on February 24, 2020 , I am still aiming at completing my CCNP R&S certification before the time in which I will also earn the CCNP Enterprise certification, a plus for me.

My Exam Schedule – CCNP R&S

CCNP R&S Route – December 2019

CCNP R&S TShoot – February 2020

 

Cisco Stackwise – Stack Master Election

by Samuel Mitchell, posted in Cisco, Routing & Switching

I was study the topic on Stackwise under the CCNP R&S Switch and saw some discrepancies on the order of the stack Master Election.

I had to resort to the Cisco 3750X configuration guide to get some clarification and this is what I discovered:

The Stack master election is done in this order:

  1. The switch that is currently the stack master
  2. The switch with the highest stack member priority
  3. The switch that is not using the default interface configuration
  4.  The switch with the highest IOS feature
    1. IP services
    2. IP based
  5. The switch uptime
  6. The switch with the lowest MAC address

I hope this clarify the stack master election.

 

Microsoft: SysInternals Suite PS Exec Command Usage

by Samuel Mitchell, posted in Microsoft, Uncategorized, windows, Windows server

I was given a task to install a agent on computers and servers using command line as during my research I discovered this tool calls PSExec from the SysInternals Suite tools.

You may ask what is PSExec? According to Microsoft, it launches interactive command-prompts on remote systems and remote-enabling tools like IpConfig that otherwise do not have the ability to show information about remote systems. In other words, PSExec tool allows the execution of commands on a system remotely as if it is on the direct system console.

There are a number of features that I love about the PSExec tool which are as follows:

  1. It can run the command as another user remotely on the local system using user interaction
  2. It allows the execution of the command on multiple computers from a list in a text file

I was given the task to install the SAP Single Sign On add-in and it was difficult because it required that it is run under a network user locally in an interactive mode.

The PSExec tool gave me the power to overcome this difficulty.

Here is the syntax of the command and the parameters I used:

psexec.exe @[file-name.txt] -u [domain\username] -p -i -h [\\server\path\batch-files.bat]

explaining each switch:

@   execute the command on each computer in the file. Each computer must be in a new line

-u   username

-p  prompt for password

-i  run command in interactive mode

-h run the command with account elevated privilege

This command will execute the script on each computer return the result as it is completed.

Please ensure it is executed on a computer that is running since it cannot be execute without the computer being on.

Common Switch Commands for the HP FlexNetwork

by Samuel Mitchell, posted in HP, Routing & Switching, Uncategorized

I have recently had to interact with an HP FlexNetwork 5510 switches and the command syntax was totally different from the HP-Aruba 2530. This article is to document the common switch commands that I use on a daily basis.

  • Show (Display) the list of interfaces and their status

display interfaces brief

  • list the directly connected devices using LLDP

display lldp neighbor-information list

  • Enter enable mode or exec privilege mode

system-view

  • Save switch startup configuration

write

  • Show the running configuration

display current-configuration

  • Configure IP helper on an interface

interface [interface_type]

dhcp select relay

dhcp relay server-address [dhcp_ip_address]

  • Configure NTP Service

ntp-service enable
ntp-service unicast-server 10.71.152.229
ntp-service unicast-server 10.220.0.35

  • Configure SSH

ssh server enable

ssh client source interface [interface]

service-type ssh terminal

  • Configure the default gateway

ip route-static 0.0.0.0 [gateway_ipaddress]

  • Configure interface as layer 2

port link-mode bridge

  • Configure interface as layer 3

port link-mode route

  •  Configure the interface as a trunk

port link-type trunk

port trunk permit vlan [vlan-id]

  • Configure the local user account to manage the switch

local-user [username] class manage
password simple [password]
service-type [options: ssh telnet terminal]
authorization-attribute user-role [role-name]

I will be adding more command as time goes by and I get familiar with the CLI.

Securing the Web management for the HP 2530 switch

by Samuel Mitchell, posted in HP, Routing & Switching, Security

Whenever you get a HP/Aruba 2530 switch out of the box, it comes default with web management enabled using http. You can easily go to the IP address of the switch to view the switch details. To secure the web portal of the switch, do the following:

  1. Log into the switch
  2. Go into configuration mode
  3. Create a self-signed certificate for secure http access

    1. crypto pki enroll-self-signed certificate-name [SWITCHNAME] subject

    2. Enter each information requested
  4. To enable secure http, use command

    1. web-management ssl

  5. To disable http for web management, use command
    1. no web-management plaintext
  6. To added a login for the web portal, use the command:

    1. password manager user-name [loginname] plaintext [loginpassword]

I hope this was useful.

Cisco 2960 Error: %ILPOWER-3-CONTROLLER_PORT_ERR: Controller port error: Power Controller reports power supply VEE under voltage and lockout

by Samuel Mitchell, posted in Cisco, Routing & Switching, VoIP

I got a report that all our VoIP phone were down in a particular area that were connected to a Cisco 2960 switch. Upon investigation,

Initially, I ran the following show commands to check the status of the ports and power:

show power inline

The switch output:

showpowerinline

It was indicating that there was no device drawing power from the switch which was strange because there were VoIP phones connected to this switch.

With further checks, I came across these errors in the event logs:

poe_error

This error was telling me either the switch power module failed or some device caused a surge in power that causes the port power module to overload.

My resolution: Restart the switch which restored the switch to normal operations.

Being curious about the error, I researched it and came across this Cisco report:

https://quickview.cloudapps.cisco.com/quickview/bug/CSCsw18530

It was stating that this error is due to a bug in a particular version of IOS for 2960 switches.

The solution is:

Workaround:

Longer cable (>50ft) seems to fix the issue in most cases.

Solution

This issue is fixed in 12,2(55)SE3 , 12.2(58)SE1 and later releases. The
following interface configuration commands have to be applied to resolve the
issue,

Switch(config)# int x/y
Switch(config-if)# power inline port 2x-mode
Switch(config-if)# shut
Switch(config-if)# no shut

The fix is present in the following platforms :

3750-E,3560-E, 3750-X, 3560-X, 3560-C, 2960S, 2960,2960C,2960X

The other platforms do not support 2X power mode and the workaround would be to
use a longer cable.