In this GNS3 lab we’re looking as the various options on how we can filter updates between EIGRP speakers and then how that affects the traffic flow (as EIGRP is a distance vector protocol we can filter updates :))This is…
Read More
This is a quick lab to look over how 6to4 tunnelling can be implemented using GNS3 1.3 and 3725 (running c3725-adventerprisek9-mz124-15.image). The topology will be as below but the important part if the colouring of the network segments and noticing the…
Read More
Quick guide to installing the quite awesome GNS3. Very similar process to Fedora 20 but this time using DNF and a small adjustment on some package names with some extras included now for dynamips to compile since it now uses…
Read More
Group Encrypted Transport (GET) VPN is slightly different and has quite different use cases from more traditional point to point IPSEC VPN where each point to point VPN is quite distinct in its own right. The most import thing to…
Read More
Dynamic Multipoint VPNs (DMVPN) offer a low admin overhead and scalable VPN solution. It is also efficient at routing traffic as it can dynamically reconfigure itself from a hub and spoke to a partial or full mesh topology! This means…
Read More
Doesnt seem to be a package for GNS3 on Fedora but installing from source is pretty straight forward 🙂 The example below uses the latest version at the time of writing which was 0.8.4 stable. wget http://sourceforge.net/projects/gns-3/files/GNS3/0.8.4/GNS3-0.8.4-src.zip/download unzip GNS3-0.8.4-src.zip cd GNS3-0.8.4-src…
Read MoreDynamic Multipoint VPNs (DMVPN) offer a low admin overhead and scalable VPN solution. It is also efficient at routing traffic as it can dynamically reconfigure itself from a hub and spoke to a partial or full mesh topology! This means…
Read MoreA quick step by step overview of how to configure the certificate server on a Cisco IOS device. The certificate server functionality was added in version 12.3(4). It is only available in in security images or higher. We can use this functionality to provide…
Read MoreManually configuring point to point IPSEC tunnels can become a big administrative burden as the number of endpoints grows. In a hub and spoke environment we can use Dynamic Virtual Tunnel Interfaces (DVTI) to help ease this burden of lots of site to site or remote…
Read MoreJust a post about the basic config and options of Cisco IOS zone based firewall using the Topology below Grab the initial configs and GNS3 .net file [HERE]. From the initial configs all interfaces have connectivity to each other. First off lets…
Read MoreJust some short notes on basic IOS vpns using the topology below as an example. All the configuration examples are for the router Lefty. Grab the GNS3 .net file and initial configs [HERE] if you want to try. The following five…
Read MoreOne problem of having a large number of routers running IBGP with each other in a full mesh is the volume of IBGP connections needed. The formula to see the number of connections needed for a full IBGP mesh is…
Read MoreSimilar to using route reflectors confederations are usually used to reduce the amount of IBGP connections needed for a full mesh. They do this by splitting an AS into multiple sub ASs. In the sub ASs created by the confederation all the…
Read More