Console to Cisco Router/Switch from Mac

Most of the time I use a Windows or Linux-based PC to access my Cisco Routers via management console. At home, I have a Laptop running Mac OSX and wanted to do the same. The steps below show how to set up a Console session to a Cisco Router using a Mac with a USB-to-Serial Converter.

Step 1. Make sure to download and install the latest driver from the manufacturer's website.
I am using a USB-to-Serial connector made by Aluratek.  It has been working great for me.

Step 2. Open Terminal. If you've never used it before, it's under Applications/Utilities/Terminal.  Or type "Terminal" in your search window.

Step 3. In the Terminal Window, enter the following:   ls /dev/tty.*

This should display a list of available serial connections on your computer like shown here:

/dev/tty.Bluetooth-Modem /dev/tty.usbserial

/dev/tty.Bluetooth-PDA-Sync

My USB-to-Serial connector is highlighted above.

Step 4. Next, type the following command: screen /dev/tty.usbserial 9600

Be sure to rename the actual connection (usbserial) to whatever it may be listed as on your computer.

This command will create a virtual session using your selected serial port, with a baud rate setting of 9600. If successful, you should be granted access to console into your router!
Good luck!

CAR vs CIR vs CDR vs MIR vs EIR vs PIR

QoS | CAR, CIR, MIR, EIR, PIR, CDR

Committed Access Rate (CAR) is used to limit traffic that can enter or exit an interface.

Committed Information Rate (CIR) is minimum bandwidth that is guaranteed to work under normal conditions, at any time the bandwidth should not fall below.

Minimum Information Rate (MIR) is minimum bandwidth, the lowest information rate will be assigned where there is congestion.

Excess Information Rate (EIR) is burstable bandwidth, CIR plus excess burst rate.

Peak Information Rate (PIR) is bandwidth will may use during data bursts when there is excess bandwidth available and no congestion also mention maximum information rate (MaxIR/MIR).

Committed Data Rate (CDR) refers also to voice and non-data packets and not only to data packets as in CDR.

All rate figure in kilobits per second (kbit/s). 

Source: http://awanetwork.blogspot.com

Error 27850 - Cisco VPN Client Installation Error

Today I ran across an issue when installing the Cisco VPN Client v5.x on my Windows7 64-bit PC.

The installation would fail and give me an error:
Error 27850: Operating System Corruption May Be Preventing Installation.

I found a great solution posted on another blog and wanted to share.

The Fix: 

1. Open Registry Editor: Type 'regedit' into the Windows Start Menu and browse for program
2. Navigate to the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network\MaxNumFilters
3. Double-click 'MaxNumFilters' and in ncrease the registry value by 1 (example: if value is 8, change to 9)

Give credit for the answer where due.  Thank this fellow!


Happy VPNing!

Day 1

Simply put...This blog to create a repository of all things that I learn and love about networking.  It really helps to "hammer-in" concepts when I write or teach topics so I hope that this blog will be a benefit to all of us.  I am open to comments to help improve what you see here and I encourage you to return.  So now....Lets Network!