Tag Archives: cisco

IPv6 Access List Basics

Posted on March 6, 2014 by

Chances are that if you have worked with IPv4 on the IOS platform for any length of time you are familiar with the access list formats, both standard and extended.  Assuming you know at least the basics of the addressing structure you should have no issue establishing similar ACLs for IPv6. Creating IPv6 ACLs The first considerations are that IPv6 ACLs have to be the “extended” format meaning the both the source and destinations have to be defined.  The ACLs also have to be named with a string as numbered ACLs are not acceptable.  The ACL name can contain numbers … Continue reading →

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Verifying Cisco IOS File Integrity

Posted on December 2, 2013 by

Moving files on Cisco devices is important to know how to do but knowing the files are free of errors is also important.  If you have every upgraded a device and find that it won’t boot because the image file corrupted you certainly know what I’m talking about.  While this happens very rarely it’s important none the less.  Additionally, knowing that you got the IOS from Cisco without it being tampered with is also important from a security standpoint. First, jump onto Cisco.com and log in with your Cisco ID.  Access the download section for a device you have support … Continue reading →

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Cisco ASA IPSec Pre Shared Key Recovery

Posted on October 24, 2013 by

The Cisco ASA firewall is one of the most common firewalls I have encountered while both working in the corporate IT world as well as in the consulting industry with small to medium clients. Most administrators enjoy working with it as it has both a fairly intuitive interface in the form of the ASDM and a powerful CLI as well. One simple but common complaint, however, is that pre shared keys are difficult to recover from the units when working with IPsec tunnels. The solution is quite simple yet often elusive. Continue reading →

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Cisco ASA Password Recovery

Posted on October 23, 2013 by

When inheriting used and abused customer networks it becomes necessary to reset passwords on devices the hard way from time to time. Fortunately with the Cisco ASA it’s still not all that complicated. You will see that with each step I included examples of the commands and the output along the way as well. Continue reading →

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