title: difference between eth0 and venet0 configuration on CentOS 6.3
body: <p>I followed <a href="http://tecadmin.net/configure-caching-name-server-on-centos-6/" rel="nofollow">this tutorial</a> to set up a nameser using BIND on my VPS built in CentOS 6.3 64-bit. I have two VPS servers, one is virtualized by Xen, and the other is by OpenVZ. I noticed that the two servers differ in their network interface: Xen server has eth0 (configured <code>/etc/sysconfig/network-scripts/ifcfg-eth0</code>), while OpenVZ has venet0 (<code>/etc/sysconfig/network-scripts/ifcfg-venet0</code>). </p>
  
  <p>When I follow that tutorial, the nameserver on my Xen server is working well, but the nameserver on OpenVZ server does not work at all. This made me think why and what difference made them work differently for the nameserver?</p>
  
  <p>The following is the result I got from "ifconfig" command:</p>
  
  <pre><code>[root@server1 data]# ifconfig
  lo        Link encap:Local Loopback
            **inet addr:127.0.0.1**  Mask:255.0.0.0
            inet6 addr: ::1/128 Scope:Host
            UP LOOPBACK RUNNING  MTU:16436  Metric:1
            RX packets:112 errors:0 dropped:0 overruns:0 frame:0
            TX packets:112 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:0
            RX bytes:10819 (10.5 KiB)  TX bytes:10819 (10.5 KiB)
  
  venet0    Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
            inet addr:50.31.115.236  P-t-P:50.31.115.236   Bcast:0.0.0.0  Mask:255.255.255.255
            UP BROADCAST POINTOPOINT RUNNING NOARP  MTU:1500  Metric:1
            RX packets:539325 errors:0 dropped:0 overruns:0 frame:0
            TX packets:368277 errors:0 dropped:80 overruns:0 carrier:0
            collisions:0 txqueuelen:0
            RX bytes:41142712 (39.2 MiB)  TX bytes:37293025 (35.5 MiB)
  </code></pre>
  
  <p>As you can see that venet0 has its inet addr:127.0.0.1. Could someone help me with understanding the differences? Thanks</p>