Category: Linux
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Root Hints On BIND DNS Servers
DNS is the resolution protocol for the interwebz. Basically, when your browser does a lookup for a URL it asks your configured DNS server to tell him what IP address the content lives at…but how does your DNS server know where to look for this information? The Root servers, of course. What are they you…
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Monitor Bind With Cacti
If someone puts in a support ticket saying they are having DNS issues with your server, what do you do to quantify how your server is acting…? This is the “boat” I found myself in a while back. I decided to use cacti to poll my devices. I happen to run Bind9. I built off…
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Centos VM Duplication Not Detecting NIC
So I duplicated a VM in VMware 5.5 that happened to be Centos 6. I added a new NIC and set the NIC type to E1000. I booted up the machine and…nothing. It didn’t see the NIC. I ran setup…and it didn’t see the NIC. After much time an annoyance I eventually issued one simple…
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BIND9 Notifications
In your bind configurations when a master DNS server makes an update it looks inside the zone file, and any DNS servers listed inside are sent a notice saying there has been an update. After this the slave queries the SOA for updates. If you happen to have an additional DNS server that needs to…
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VLANs In Centos 6
Creating VLANs in centos 6 is simple…well, it’s supposed to be. # cat /etc/sysconfig/network-scripts/ifcfg-eth1.58 VLAN=yes DEVICE=eth1.58 NM_CONTROLLED=no ONBOOT=yes BOOTPROTO=static IPADDR=x.y.z.w NETMASK=a.b.c.d For me, though, not so much. I have a CSV with about 200 VLANs that need to be created, so I wrote a quick autoit script to whip up the config files…no biggie. I…
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Installing Rancid On Centos
I actually installed Rancid on my newest CactiEZ install. Rancid is a device configuration backup service. To view the CVS files that are created I used CVSweb. I started with this tutorial to install Rancid on Centos…an extremely useful tutorial. Once this was working I pulled the newest files from the CVSweb site. I dropped…
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Simulate WAN Delay, Loss and Bandwidth
I recently had a question about how to simulate the delay presented by a point to point circuit so someone could test their application going from one facility to access a SQL DB in a backup colo. I did a quick google and ended up with several great options. Netem One option I found, but…