Elvenware

Networks

Welcome to Networks

Network and Router Basics

You can run the PING command to find out if you are connected to the Internet. Also, run ifconfig on Linux, and ipconfig /all on Windows.

Configuring a router, view the DHCP page

Figure 0X: Configuring a router, view the DHCP page

Configuring a router, view the page

You can have more than one router on a
computer.

Figure 03: There are two active network adapters on my system. One is for my ethernet cable, the other for wifi. If I connect to a VM, and choose Realtek Family Controler, but there is no Ethernet cable plugged in to my laptop, then I am going to have a trouble. As a result, I usually use WiFiLink because it works even if the cable is not plugged in. However, on my machine, it often seems like it is either/or, not both. In other words, when I plug in my ethernet cable, I loose my WiFi. Therefore, I need to be sure I am choosing the right option. Fortunately, VirtualBox lets you switch adapters while a VM is loaded. Notice in this screen show that some options are grayed out. That is because the VM called Ubuntu 32 Minimal is currently running. But even though some options are grayed out, the option to choose a new adapter is still available, and I can switch back and forth at run time. However, it often takes about 15 to 30 seconds before the change registers with the VM. So you need patience.

The Windows Device Manager with multiple NICs

Figure 0X: The network settings page

Notes on Virtualization Networking Deep Dive

Layer-3 networking, HSRP (Hot Swap Routing Protocol) or\ VRRP (Virtual Routing Redundancy Protocol), link aggregation,\ VLANs and VLAN

a\ pile of gigabit copper ports or a smaller number of 10G\ copper or fiber Ethernet ports.

If you have the\ budget to deliver multiple 10G links to each virtualization\ host, then by all means, go that route

The use of VLANs in a virtualized infrastructure is a must.You can also use the enhanced control afforded by VLANs\ to constrain certain VMs to their own specific network, and\ in some cases, create airlocked VLANs that can be used in\ development environments. There’s

There are three main methods\ of delivering shared storage to a virtualization host: iSCSI,\ NFS, or Fibre Channel.

If NFS is the choice, then there isn’t much to do on the\ host side, as the storage array will be busy handling the\ NFS serving, with the virtualization host acting as the client.\ There are definitely benefits to using NFS as a VM store,\ such as ease of backup and restore. But there are detriments\ as well -- notably, the inability for some virtualization solutions\ to create raw disk mappings on NFS-based storage.

If it’s 10G, then in most cases it’s as simple\ as connecting two 10G links to the core switches with\ VLAN trunking and link aggregation.

To sum up the basic host configuration: six 1G interfaces\ in bonded pairs for front-end, back-end, and storage\ links. For a 10G-equipped host, we’ll have just the\ pair of 10G links configured in a failover or bonded pair.