There is a random bug that sometimes occurs with Vbox NAT mode DNS, although it has never happened in the past and Vbox was working fine until recently.
The symptom is that you can see it does get an IP+ DNS from the Vbox NAT DHCP.
Below we use resolvectl dns and verify the DNS server is set to 10.0.2.3 which is the DNS from Vbox NAT. We can ping it but it does not respond to any DNS requests when we use dig @10.0.2.3 realtechtalk.com........
Why choose OpenVPN instead of a firewall appliance?
OpenVPN can be a reliable and easy replacement for traditional hardware or just be an additional tool that your company uses so that the firewall can focus on its job rather than acting as a VPNappliance at the same time.
When comparing OpenVPN with traditional firewal........
This often happens if you are adding a secondary route, especially with Linux source based routing.
ip route add default via 10.10.10.254 table 10
RTNETLINK answers: Network is unreachable
If that happens you will probably find that it is unreachable because your NIC does not have an IP in the 10.10.10.0/24 range so just assign an IP in that range to your NIC and try again.
eg. ifconfig eth0 10.10.10.254 netmask 255.255.255.0 up........
This will find all tap devices and try deleting all of them. Of course don't run this if there is a chance an unused tap device is necessary and would not be created by the script ro application using it.
for tap in `ifconfig -a|grep tap[0-255]|awk '{print $1}'`; do
tunctl -d $tap
done........
The net-tools command brings back all of the oldschool tools that we're used to:
/bin/netstat
/sbin/ifconfig
/sbin/ipmaddr
/sbin/iptunnel
/sbin/mii-tool
/sbin/nameif
/sbin/plipconfig
/sbin/rarp........
Sometimes if you have a very basic configuration OpenVPN on the client side for some reason sends all traffic to the OpenVPN server IP through the tun0 which is of course impossible and creates a block or routing loop.
This is because you need to use your normal ISP/LANgateway to hit the OpenVPN server if it is remote/offsite as is usually the case. So if you are connected to the OpenVPN through say a tun0 device and your routing is set to connect to the OpenVPN&nbs........
Centos 7 is no cakewalk, there are many fundamental features and basic utilities that are missing or even completely renamed or different!
Another shocking thing is to check your NIC it is set by default to not turn on when booting!
And by the way there is no more standard eth0 the NIC convention is now "enp0s3"
vi /etc/sysconfig/network-scripts/ifcfg-enp0s3........
Thsi is very handy when doing your own kernel development.
-m specifies how much ram (in the example it is 768MB)
-kernel specifies the path to the kernel file
-net tap,ifname=tap1,script=no (the ifname=tap1 is what you need to change and setup manually).
*Run "tunctl -b" to create a tap device and use the one it gives you for ifname=
Enable networking to the outside like this:
*Note we assume that your bridge is br0 i........
If you move your hard drive(s) around to other computers/servers, you'll find that your eth0 keeps getting higher, the first time it will become eth1 and then eth2 etc and even higher if your server has dual or quad NICs. The reason is that udevd basically assigns eth0 tot he first NIC it finds and remembers it, if it encounters a NIC with a differentMAC, it assigns it one higher (eg. eth1).
See the example below, I have eth2 now so how doI fix it?........
2010:09:09-22:22:11: The ip of this machine (xx.xx.xx.xx) does not match the ip in the license file.
Check the value of your ethernet_dev=venet0:0 setting in your /usr/local/directadmin/conf/directadmin.conf file and the output of /sbin/ifconfig
Solution
/usr/local/directadmin/scripts/getLicense.sh........
After installation Directadmin does not work on OpenVZ VPS when browsing http://ip.ip.ip.ip:2222
service directadmin status
directadmin dead but pid file exists
tail /var/log/directadmin/error.log
Check the value of your ethernet_dev=eth0 setting in your /usr/local/directadmin/conf/directadmin.conf file and the output of /sbin/ifconfig
2010:07:10-12:44:01: ioctl can't find........