Fast Down Detection

Fast down detection or sub-second link failure detection is needed in a modern networks. Network operators of modern networks require that they can detect failure in sub-second and react to either soft or hard failures as quickly as possible. The following are the two categories of fast down detection. 1.

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UNetLab Common Issues

These are the common issues I encountered in setting up UNetLab and how I fixed these issues. I’m sharing this so UNetLab users will benefit from it. I will constantly update this list as I progress. Issue 1: UNetLab is complaining about – Neither intel VT-X or AMD-V found. Solution:

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H323 NAT address not configured

Issue: Cisco TelePresence endpoint cannot make H323 point-to-point call to another Cisco TelePresence endpoint. Both endpoints are standalone H323 and no Gatekeeper. Symptom is when calling from either endpoint the call automatically get disconnected after few seconds. Platform: EX, SX, MX and Integrator C series TelePresence endpoints Software version: Any

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Anonymous SIP Calls

This document walks you through on how to implement anonymous SIP calls in a Cisco Voice Gateway (e.g 28xx/38xx, 29xx/39xx). 1. Enable privacy at the header level in the SIP message. This setting affects all calls (applied globally). voice service voip sip privacy header 2. This dial-peer configuration prevents the

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OpenVPN DNS Issue

Issue: OpenVPN connects successfully but cannot resolved hostnames when browsing. It looks like an OpenVPN DNS issue. Platform: Ubuntu 14.04 LTS (Trusty Tahr) Software version: OpenVPN 2.3.4 OpenVPN logs indicated the DNS configuration was successfully pushed from OpenVPN server to client. Tue Oct 14 05:08:39 2014 SENT CONTROL [changeme]: 'PUSH_REQUEST'

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