Cisco IOS Diagnostic Tools
There are certain a number of diagnostic tools that can be used to troubleshoot and monitor the different elements of a network. This article takes a look at a number of the built-in tools/command that exists within Cisco IOS. Any experienced IOS engineer knows that many issues can be diagnosed using only the tools that exist within the IOS itself; the target audience of this article includes engineers with less experience looking to become more familiar with the available tools and those preparing for the CCNP TSHOOT exam.
Show Processes CPU
One of the most basic commands to run on a Cisco device is show processes cpu. In its full view the command will show all of the active processes on a device and how much of the processor time the process is taking both currently and historically. Figure 1 below shows a shortened version of the command:
This command would typically be used when troubleshooting a problem with a device that is having trouble performing basic functions; for example if a router is having trouble forwarding and routing pa
Cisco Linksys Secret CLI
Cisco's consumer branded "Linksys" SRW, SFE and SGE switches have a "hidden" light-weight command line interface (LCLI) which is very similar to Cisco's IOS command line environment. Here's how to access it:
1. SSH, Telnet or Console into your switch as you normally would. Note: Do not use the web interface.
2. Login to the menu system using your existing admin account.
3. Once logged in type:
# execute
4. You should receive a response that says "Operation Complete".
5. At the Switch "Main Menu" press:
CTRL+Z
6. A carrot (>) command line will appear. Type:
# lcli
Then press enter.
7. Login again using your admin account and you will be in the Light-weight Command Line Interface (LCLI).
8. Type: ? for possible commands.
Note: There is no need to "write mem", all changes are committed immediately. "show startup" will dump the switch configuration, to disable console logging type "no logging console", 'show bridge addr" will dump the CAM table, "show inter status" which show you switch port status.
Using a Dell Wireless 5620 EV-DO-HSPA in Thailand
The Dell Wireless 5620 Multi-Mode Gobi Mobile Broadband Mini-Card is a great way to add mobile broadband (HSDPA, EVDO, EDGE, 3G) to your Dell Latitude E series laptop without having to use an external modem or Internet tethering.
The modem is generally shipped with an AT&T configuration profile so I've drafted up some instructions on how to make the card work with other providers, specifically those in Thailand.
First of all, install the Dell Mobile Broadband Utility (DMBU) also known as: R275082.exe from http://support.dell.com. This is the "Dell Mobile Broadband Utility" also referred to as the Novatel Wireless HSUPA manager.
Once you have installed the Dell Mobile Broadband Utility (DMBU), reboot your machine then insert your True, AIS or DTAC SIM card into the rear of your laptop. On the Dell Latitude E6400 and E6410 the SIM card slot is located underneith the battery. Reboot your machine again.
Open the DMBU and select the wireless icon in the top left corner. Select "Settings" then "Network Selection" then select:
Provider: Generic
Technology: UMTS
Region: EU
Version: 0A090012
Then click "Load".
Subnetting Notes for Beginners
Here are some notes on IP subnetting for beginners.
1 and 1 = 1, everything else = 0.
An IP v4 IP address is 32 bit and made up of four octets, each 8 bits long. The minimum octet value is 0 and the maximum octet value is 255. 4 x 8 = 32.
The decimal notation to binary chart for IP subnetting is: 128, 64, 32, 16, 8, 4, 2, 1 The sum of which is 255 (128+64+32+16+8+4+2+1). 128 is the first 1 in binary chart, 1 is the last.
To convert a IP address from decimal to binary separate each octet, e.g. 203.170.50.1
203 = 128+64+8+2+1 or 11001011
170 = 128+32+8+1 or 10101001
50 = 32+16+2 or 00110010
1 = 00000001
1 and 1 = 1
1 and 0 = 0
0 and 1 = 0
0 and 0 = 0
If your IP address is 192.168.183.91 and your subnet mask is 255.255.255.224 you can find the network address as follows: