When you have a network switch which is capable of 802.1Q, also known as VLAN tagging or trunking, and you want to transport a certain VLAN directly into a VM in VMWare Player or Workstation or VirtualBox you have to do some additional configuration. Standard desktop versions of Windows strip off VLAN tags. You've probably already tried to enable Packet Priority and VLAN. People who are using Wireshark encounter the missing VLAN tags possibly as well and could follow the solution as wel below.

All you have to do is this (it took me a while I found this one out for my Intel(R) Gigabit CT desktop adapter):

1. Backup your Windows registry;

2. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\ControlSet0001\Control\Class\{4D36E972-E325-11CE-BFC1-08002bE10318};

3. Open the tree and you'll see folders like 00xx;

4. Look for the folder containing your network card/NIC, displayed as DriverDesc

5. Modify/add a REG_DWORD 32bit named MonitorMode with value 1 (alternatively Realtek or other cards use REG_DWORD MonitorModeEnabled);

6. Reboot and you should be done (or enable/disable NIC).

Happy tagging!

 

By default Ubuntu comes with IPv6 enabled. When you don't have an IPv6 Internet connection or you want to disable IPv6 from a security perspective, it's easy to disable:

1. sudo su

2. echo "net.ipv6.conf.all.disable_ipv6 = 1" >> /etc/sysctl.conf

3. option 1: reboot

3. option 2: sysctl -p

When you have an SNMP polling service running like Cacti, you can poll your Ubuntu machine's easily in a few steps.

1. install snmpd (snmp deamon)
sudo apt-get install snmpd

2. now edit the settings file
sudo vim /etc/snmp/snmpd.conf

3. comment out when the SNMP polling server is not running on the local host:
#agentAddress udp:127.0.0.1:161

4. add listen on all interfaces for both IPv4 and IPv6 UDP 161
agentAddress udp:161,udp6:[::1]:161

5 option 1. scroll further down and add above "rocommunity secret" (your polling community string "secret" and your polling server ip address i.e.; Cacti):
rocommunity secret 192.168.1.100

5 option 2. or with FQDN
rocommunity ForgeMe123 cacti.example.com

6. Save the config and restart services:
sudo service snmpd restart

Out of the box Ubuntu 14.04 LTS supports stateless IPv6. This means you can run IPv6 without DHCPv6 server. If you want to run an DHCPv6 server to automatically register IPv6 addresses in your local DNS, or you want to port forward certain ports for a service (webserver / bittorrent) to a specific IPv6 address (DHCPv6 reservation) you end up having to set up a DHCPv6 statefull client. This is quiet easy; assuming you've already got an DHCPv6 server running in your network. In this example we're using "wide dhcpv6 client":

sudo apt-get install wide-dhcpv6-client

sudo vim /etc/wide-dhcpv6/dhcp6c.conf

modify the contents of this file so it looks like this:

# Default dhpc6c configuration: it assumes the address is autoconfigured using
# router advertisements.

profile default {
information-only;

request domain-name-servers;
request domain-name;

script "/etc/wide-dhcpv6/dhcp6c-script";
};

interface eth0 {
send rapid-commit;
send ia-na 0;
request domain-name-servers;
};

id-assoc na 0 {};

Just restart the services and you're done.

sudo /etc/init.d/wide-dhcpv6-client stop
sudo /etc/init.d/wide-dhcpv6-client start