Showing posts from November, 2014

Advertising a default route over BGP

JEREMY L. GADDIS , owner of  the blog at, has written an excellent tutorial on how to advertise a default route over BGP.

The most important part of the tutorial to actually advertise the default route is the following:
R3(config)# router bgp 33 R3(config-router)# neighbor default-originate R3(config-router)# neighbor default-originate SOURCES : Advertising a default route over BGP

How strong is SSL encryption ?

Ever wondered how strong is the SSL encryption we use everyday in our web browser and email clients (e.g Outlook, ThunderBird)?

Q: How secure is the encryption used by SSL?A:  It would take significantly longer than the age of the universe to crack a 128-bit key.

Understanding SSLSSL uses public-key encryption to exchange a session key between the client and server; this session key is used to encrypt the http transaction (both request and response). Each transaction uses a different session key so that even if someone did manage to decrypt a transaction, that would not mean that they would have found the server's secret key; if they wanted to decrypt another transaction, they'd need to spend as much time and effort on the second transaction as they did on the first.  Of course, they would have first have to have figured out some method of intercepting the transaction data in the first place, which is in itself extremely difficult.  It would be significantly easier to tap your p…

How to solve the Blue Screen of Death when Using GNS3 on Windows 7 or 8

When you are using GNS3 on Win 7/8 and if you stop the router, you get a blue screen saying your PC ran into some problem with the following error:
Your PC will restart after this error :(
After doing some research on the GNS3 forum and reading the users experience, I found 2 solutions to this problem:
1. Run GNS3 on a LINUX Distro e.g DEBIANor UBUNTU (FYI: A Linux Distro is always more stable than Windows)
2.If you are not comfortable with LINUX then you can still use WINDOWS but make sure you run the following CISCO IOS Images according to a post (please see extract below) on the CISCO LEARNING NETWORK  by Navneet.Gaur :
“These are the stable working IOS images for GNS 3. I have some of them as I own the routers. 1 Cisco 2691 Router | 2600 Series - Extremely stable      c2691-adventerprisek9_ivs-mz.124-9.T7.bin 2 Cisco 3640 Router | 3600 Series      c3640-ik9o3s-mz.124-25.bin 3 Cisco 3725 Router | 3700 Series - For MPLS      c3725-adventerprisek9-mz.124-15.T5.bin 4 Cisco 72…