Student Setup (Juniper/Cisco and KVM)

Introduction

The goal of this exercise is to set up the KVM host and Cisco switch so that they can talk to each other. In later labs, the switch will be used to isolate traffic between virtual machines on the KVM host using VLANs.

What is a VLAN?

A VLAN is a Virtual Local Area Network where multiple devices can be grouped together to create a single logical unit. You can set multiple groupings so that you won’t need a separate device for each local area network or LAN.

Prerequisites

This lab requires no prior experience or knowledge. However, there will be links to skills that will be required for this lab. When you finish this lab, you should be able to:

Set up basic configuration for a switch
Configure switch interfaces
Configure interfaces on a KVM host

Configuring the Switch

In this lab you will be configuring a Juniper switch. This will be done via console, once we have the switch configured and have done Juniper Lab we can being setting up the NeatRack Lab to eventually have SSH access to everything. There are two ways to get console into the switch.

Once you are consoled into the switch, you may have to press ENTER to receive output. Since we are using a default configuration, you’ll be able to login with the root username with NO password. If you are prompted for a password, please notify the NeatRack trainer.

Depending on the equipment on hand, there are two guides to follow, one for Juniper and the other for Cisco:

Before Configuring the KVM Host

When we first got the KVM host set up, we had plugged the host directly into a switch to allow the KVM host to obtain a DHCP address in order to finish setting it up. Now we need to adjust the connections for this and future labs to work correctly. We are going to move the Ethernet cable that connects the host to the switch we used to obtain a DHCP address and move it to one of the trunk ports on our switch that we just configured. Then, we will connect our switch via one of the access ports we’ve configured to the switch that gave our host the DHCP address. Our physical set up should now look something like the following.

Configuring the KVM Host

Log into the KVM host with the username and password you put on the KVM host when you set it up in the Setting Up the KVM Host lab.

Now, we’re going to edit the interfaces file using nano:

test@test:~$ nano /etc/network/interfaces

Remove everything below the loopback line and replace it with this:

Note: Depending on the hardware your server is using, the primary physical interface might be called something different from eth0. Use the command “ip a” to list your interfaces. It probably looks like “enp2s0”, “eno1” or “ens2”. If that is the case, everywhere that “eth0” is used in the configuration below, replace it with whatever your interface is. Also, you need to make sure you’re using the correct vlan and vmbr for your Internet connection. You may have to ask a network engineer which vlan and vmbr you’ll need to use.

auto eth0

iface eth0 inet manual

up /sbin/ifconfig $IFACE up

## Server LAN

auto vlan60

iface vlan60 inet manual

vlan-raw-device eth0

auto vmbr60

iface vmbr60 inet static
    address 172.30.60.10/24

    bridge_ports vlan60

    bridge_hello 2

    bridge_maxage 12

    bridge_stp off

    bridge_fd 9

    up /sbin/ifconfig $IFACE up || /bin/true

## Internet Connection

auto vlan14

iface vlan14 inet manual

    vlan-raw-device eth0

auto vmbr14
iface vmbr14 inet dhcp

    bridge_ports vlan14

    bridge_hello 2

    bridge_maxage 12

    bridge_stp off
    
    bridge_fd 9

    up /sbin/ifconfig $IFACE up || /bin/true

We put dhcp on the vmbr interface instead of the physical interface because if we need to use the same vmbr for a VM, we’ll be able to easily get a DHCP address. When you put an IP address attained from DHCP on a physical interface and then try to use DHCP on a vmbr or vlan interface, you will not get a DHCP address, because the physical interface will be preferred over the vmbr/vlan interface.

Now, type this to restart networking so that vmbr60 and vmbr10 can be used:

service networking restart

This command is alright to use since we don’t have any VMs running, however, when we begin to add more, you will not want to the use this command. This will take down all of the interfaces, which could bring down other VMs. Instead, we use:

ifup vlan14 && ifup vmbr14

ifup vlan60 && ifup vmbr60

We do this so that we only have to bring up an individual interface instead of restarting the whole network. Take note that you should bring up the vlans before the vmbrs because the vlans are what the vmbrs are tethered to. Also, we can bring up both the vlan and the vmbr without having to type in each command individually with the use of &&. This makes it to where we can run two commands on the same line, assuming that the first command is completed successfully. This saves time and typing when you bring up vlans and vmbrs in this way.

Note: We are using vmbr60 as our dhcp server vlan, and this sets us up when we begin to create the VM we are going to be using to make a DHCP server.

If you have your switch connected to an ethernet port that has access to the internet and you followed the above steps, you should now have internet access. You can test this by checking that you have an IP address on vmbr10 with the “ship” command, then running “ping 1.1.1.1”. If you see responses coming in, then it is working. In the event that this doesn’t work, Internet access is nonessential, so see if you can figure out how to fix it, but don’t worry if you can’t. Hopefully, as we progress through the labs, you’ll get a better understanding of what these steps do so you can troubleshoot.