Monthly Archives: April 2010

Troubleshoot NAT

Definitions NAT Types Static NAT — A one-to-one mapping of private to public IP addresses, best used for a device that needs access from outside the AS. Dynamic NAT — A dynamic one-to-one mapping between private and public IP addresses, … Continue reading

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Troubleshooting Spanning Tree Protocol

Spanning Tree Protocol Basics: In a layer 2 environment with no routing, active redundant paths are neither allowed no desirable, because the can cause loops. Because a switch only segments collision domains it does not segment broadcast domains. STP helps … Continue reading

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DocMgr with AD Authentication

Over the past couple of days I hacked an older version of DocMgr to authenticate users to Active Directory. I thought it might be interesting for some readers to see my thought process, hence this post. All of the scripts … Continue reading

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Linux DBI::ODBC AS400

At the Circus we are removing the last vestige of our OpenLDAP implementation and moving it to Active Directory. As a result I’m going to document some of the odd scripts I have written as glue to help keep things … Continue reading

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Troubleshoot Router Performance

There are three general causes of router performance issues: 1. High CPU load 2. Router packet switching mode 3. Excessive memory use Processes that can be a cause of high CPU load: • ARP Input process — Heavy traffic load … Continue reading

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Security by Obscurity

It kills me. One of our Windows administrators went to class and “learned” that you should not give meaningful names to servers on your network because that would make it too easy for some cracker find his or her way … Continue reading

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EIGRP Troubleshooting

2010-04-14 07:45:39 EIGRP Troubleshooting Enhanced Interior Gateway Protocol (EIGRP) EIGRP is a Cisco proprietary hybrid routing protocol or an advance distance vector routing protocol. There are four components that make up EIGRP: 1. Protocol-dependent modules — Supports several routed protocols. … Continue reading

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Troubleshoot BGP

2010-04-13 16:07:12 Troubleshoot BGP BGP is a path-vector routing protocol. Routes are tracked in terms of the AS they pass through, and routers avoid loops by rejecting routes that have already passed through their AS. Definitions Synchronization — Before iBGP … Continue reading

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Wednesday Night Worlds

One of my friends got onto me that my blog was all about work. He wanted to read stories about some of my cycling adventures. Rather than launch into stories about riding across America, I’ll start with some stories from … Continue reading

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Troubleshoot OSPF

My notes for EIGRP felt like I was just regurgitating the Key Points from the book. So with OSPF I read the book and looked at the command output, then decided to copy my notes from the BSCI and edit … Continue reading

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