Troubleshooting Cisco Network Elements with the USE Method

The USE Method is a model for troubleshooting a system that is in distress when you don't know exactly what the nature of the problem is. For example, if users within a specific part of your network are complaining of slowness, disconnects and poor application performance, you can probably isolate your troubleshooting to 2-3 switches or routers. However, since the problem description is so vague (we all love the "it's slow!
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Juniper Olive

Olive refers to a regular PC or virtual machine that is running Juniper Networks' JUNOS software. Juniper created Olive early on so they could perform testing of JUNOS during development. These days Olive is deprecated in favor of cheap, low-end M and J-series routers but is still used by people wanting to evaluate/test JUNOS or those who are studying for Juniper certifications. For the most part Olive is fully functional as a basic router.
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ZFS File Server

Specifications Total storage raw: 10TB Total storage usable: 5TB Case Norco RPC-4220 - 20 hot-swap bay, 4RU chassis PSU Corsair HX 750W Motherboard Supermicro X8STE - single socket 1366; 2x Intel 82574L GigE NIC; Matrox G200 GPU CPU Intel Xeon E5620 Westmere 2.4GHz Quad Core RAM 24GB (6x4GB) Kingston 240-pin DDR SDRAM ECC Unbuffered Controller Cards Intel SASWT4I (LSI SAS1064E chipset) PCIe x4 4-port SAS HBA LSI 9201-16i 6GB/s PCIe 2.
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OpenBSD Compact Flash Firewall

The goals of this project was to build a low-power, small form factor machine that runs OpenBSD and acts as a firewall/router in a home network or small business setting. This page walks through the hardware I chose and the process I use to get OpenBSD running on the CF card. Table of Contents Hardware Operating System System Operation Hardware The design has gone through two generations of hardware now.
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OpenBSD IPsec Tunnel Guide

This guide will explain how to setup a site-to-site IPsec tunnel (i.e., tunnel mode IPsec) between two OpenBSD gateways. Throughout this document there are example configs shown, some of which contain secret key data. DO NOT use these example keys! Create your own (as shown) and keep them private. The Tools OpenBSD ships with all the tools needed to begin using IPsec. OpenBSD does not require a kernel recompile, software installtion, 3rd-party modules or anything else to get IPsec up and running.
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OpenBSD CARP Notes

CARP is the Common Address Redundancy Protocol. It's a secure, free alternative to the Virtual Router Redundancy Protocol and the Hot Standby Router Protocol. CARP was created and is maintained by the OpenBSD project. The notes here apply to OpenBSD 5.0 and higher. Protocol Information Virtual MAC Address The virtual MAC is in the format 00-00-5e-00-01-XX where the last octet is filled in by the CARP vhid. IP Protocol CARP uses IP protocol number 112 (0x70).
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OpenBSD OpenBGPD Notes

OpenBGPD is a free, open-source implementation of the Border Gateway Protocol Version 4. It was created and is maintained by the OpenBSD project. The notes here apply to OpenBGPD as found in OpenBSD 4.0 and higher. Path Selection Process OpenBGPD will only ever install one route in the route table for a particular destination network (prefix). If OpenBGPD receives information about that prefix from more than one peer, a decision must be made on which one to use.
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OpenBSD SNMP MIBs

The following SNMP MIBs and the accompanying code that extend the Net-SNMP daemon allow administrators to query information from various OpenBSD subsystems. Currently, stats can be queried from: Packet Filter The kernel sensors framework Common Address Redundancy Protocol (CARP) These MIBs are being integrated into OpenBSD's own snmpd. OpenBSD 5.1 has the kernel sensor and CARP MIBs. OpenBSD 5.1-current has and the future 5.2 release will have the pf MIB. See this post for a bit more detail.
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NetPacket PERL Module Enhancements

NetPacket provides a base class for a cluster of modules related to decoding and encoding of network protocol packets. Each NetPacket descendant module knows how to encode and decode packets for the network protocol it implements. Protocols that NetPacket can encode/decode include IPv4, TCP, UDP, ICMP, Ethernet, and ARP. I've written three additional modules for NetPacket that allow the encoding/decoding of IPv6, ICMPv6, and OpenBSD's Packet Filter binary log files. I've also made numerous changes to existing modules, including fixing spelling mistakes, bug fixes, and documentation enhancements.
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Monitoring BIND9

The goal here is to monitor DNS servers running BIND version 9 and graph the various statistics that it records about itself. The statistics will be made available to the Net-SNMP daemon by a script. From there, the data can be polled by whatever NMS you choose to use. Table of Contents Getting Stats from BIND Serving Stats via SNMP Download for BIND 9.4 Download for BIND 9.6 and Newer Notes Getting Stats from BIND BIND stores a number of statistics internally.
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