Technology Insights

Setup dhcp3 Server To Listen On eth1

Earlier I was setting up a PXE boot server that was connected to two networks and wanted to hand out DHCP addresses only on the second interface which in this case was eth1. The primary interface on the server is eth0 however that Ethernet port is attached to a switch that already has a DHCP server connected to it so I needed to make sure that the DHCP server only replies to requests on eth1. Use the dhcpd.conf configuration option below to specify the Ethernet interface that dhcpd will listen for and reply to DHCP and/or BOOTP requests.

Information Security

0trace Error In Backtrack 5: 0trace.sh Probe Rejected By Target

Previously I wrote a brief article on 0trace in Backtrack 4 which can be located here however in the process of writing an updated article for Backtrack 5 I noticed that 0trace was no longer working. Every single time I would attempt to run an accurate trace through a firewall the results would come back empty and display “Probe rejected by target.” At first I was thinking maybe companies have really tightened down their firewalls however that didn’t make any sense because of how 0trace works using a standard port such as port 80 to allow traffic to pass because the servers function is to serve web pages. Below I describe the error in more detail and how you can resolve it.

Week One: Initial BigIP LTM VE Configuration Using Bigpipe Commands To Add VLAN & Self IP Address

The below article is the first in a series of articles to help get you more familiar with the BigIP BigPipe commands used to manage an LTM VE or Local Traffic Manager Virtual Edition installed in VMWare Player as noted in this article. After following the steps in this article you will have created two VLAN’s (Virtual Local Area Networks) and added an IP address to each VLAN which will be the foundation of the series of articles that will help you setup and configure your LTM VE to do basic load balancing followed by other articles that build on that foundation. The future articles will become more in depth by first taking you through basic troubleshooting steps using and overtime using more advanced techniques for troubleshooting issues on a BigIP Local Traffic Manager.

Technology Errors

Ubuntu 10.4 eth0 – not available! – RTL-8139/8139C/8139C+ (rev 10)

I had a customer today who brought in a laptop and wanted to switch over to Ubuntu linux. I always try to go the extra mile for people who want to convert to Linux. After installing Ubuntu 10.04 LTS, I rebooted and to my dismay the wired (eth0) interface was not working. I always run into wireless problems with Linux but its pretty rare that a wired interface doesn’t work. Below I show the fairly simple fix.