Technology Errors

Cisco Catalyst 2950: When no shut One VLAN The Other VLAN Goes Down

A couple days ago I was working on the network at the computer shop and ran into an issue configuring the Cisco Catalyst 2950 switch we have on part of the network. The goal was to set up three VLAN’s to segregate traffic on three segments of the network that each have their own purpose. One of the VLAN’s is used by the employees, one VLAN used for the public, and the third VLAN used to host servers that provide various services. I was in a rush to minimize downtime when I was configuring the access to the 2950 switch itself and attempted to assign an IP address to two of the VLAN’s. Below I explain the details of the issue that caused as well as an explanation of why this won’t work.

Technology Errors

Gentoo Linux: eth0 Stops Working During Install Using Minimal Install CD

I started an install of Gentoo Linux this morning on a desktop at my house so I could test some browser stuff that purehate was seeing via his Gentoo laptop. I don’t think I have ever installed Gentoo but its possible a couple years back I installed it in the same scenario. Anyway I decided to download the x86 minimal install CD for the installation. After it was burned to CD I booted my desktop up and started the install. Once it was booted I configured the network interface, which in this case was eth0, and was able to test without issue to the Internet using ping. I proceeded with the installation including writing the partition table, creating the file system, and mounting my drives. The next step involved using links to open a gentoo.org URL to select a mirror and to my surprise it failed. Below I go into detail about the problem I ran into and the steps I took to resolve the issue. 

Technology Insights

CentOS 5.2 /etc/sysconfig/networking

The file located in /etc/sysconfig/networking/profiles are created by the GUI network interface management tool. These files should not be edited manually and when changes need to be made they should be made directly to the files as shown below. CentOS 5 is easy to get around from the command line and it is beneficial to understand each of the below files if you are going to manage a server.

Need to make a change to hostname?
First modify /etc/sysconfig/network and modify the following line:
HOSTNAME=your.hostname.here