VLAN atau Virtual LAN adalah sebuah model jaringan yang membagi beberapa jaringan secara logikal kedalam beberapa jalur yang berbeda tapi tetap lewat perangkat penghubung yang sama. Dengan menggunakan VLAN maka kita bisa membuat beberapa segmen jaringan yang berbeda subnet berada dalam jaringan switch yang sama.
Beberapa keuntungan menggunakan VLAN adalah :
- Mengurangi broadcast domain, sehingga meningkatkan keamanan dan performa jaringan
- Pengelolaan jaringan menjadi lebih mudah, karena user dengan kebutuhan jaringan yang sama akan berbagi VLAN yang sama.
It’s now time to start placing some VLAN’s onto our switch. A good starting point is why do we use VLAN’s?
Well a VLAN enables us to:
- Logically segment a switch into smaller switches, much same way that ESXi allows you to run multiple virtual machines on the same physical hardware.
- Create logical boundaries so that traffic from one VLAN to another VLAN is permitted or not permitted e.g. User VLAN accessing Server VLAN.
- Reduce the broadcast domains, in the same way that a switch creates a separate collision domain for each device plugged into it. A VLAN reduces the ARP broadcasts sent out.
Before we move any further, we need to understand what purpose the VLAN’s will serve in our environment and what they will be assigned too. For me, it’s quite straight forward, the HP v1910 will be used as my main home lab switch and as such I need a VLAN for the following purposes:
- HP Fail Over Manager
With this in mind, I would highly recommend creating a network table containing your VLAN Names, VLAN ID, Subnet and Switch IP Address. You may ask why do you bother? Well I deal with large number of clients infrastructure and I often find that I get confused as what subnet’s are doing what!
You will notice that I have assigned an IP address to the switch on every VLAN. The reason for this is the HP v1910 can also do layer 3 static routing so in my home environment the switch is the default gateway as well.
Layer 3 Static Routes
OK, lets login to the HP v1910 24G using the IP address and username/password we assigned previously.
Why use layer 3 static routes? Well I want to be able to route between VLAN’s. This is critical for my HP Failover Manager (FOM VLAN) which needs to be in a logical third site to communicate with the HP Virtual Storage Appliance (iSCSI VLAN). For each device on each VLAN they will use the switch as there default gateway. This means that the network traffic will only leave the switch if it has a destination subnet for which it is not responsible e.g. the internet.
To do this, click on Network from the left hand panel then IPv4 Routing
Click Create in the Destination IP Address enter 0.0.0.0 Mask enter 0.0.0.0 Next Hop enter 192.168.37.254 Select Preference and enter 10
So what are we actually doing? Well we are saying to the switch for ‘any destination IP address’ and ‘any subnet’ send all that traffic to this router/firewall whose IP address is 192.168.37.254 (next hop).
Hopefully it should look something like this.
Cool, let’s test it. Change a computer to use the HP v1910 24G switch as it’s default gateway.
We should now be able to ping the switch, the switches next hop and also something out on the internet.
Boom, it’s all working, let’s move on!
Hopefully, you have already decided on your VLAN configuration and IP address’s for the switch. So let’s crack on and start configuring.
Select Network from the left hand menu then VLAN and then Create
My first VLAN ID is 10, so we enter this and click Create to the left hand side. Next Modify the VLAN description from VLAN 0010 to iSCSI and then click Apply.
Rinse and repeat until you have entered all of your VLAN’s into the switch. Here’s one I made earlier.
TOP TIP, don’t forget to click Save in the top right hand corner on a regular basis.
Great, we have created the VLAN’s now we need to assign them to some switch ports. We need to understand what happens when we change the port characteristics. The options we have are:
- Untagged – what ever device we plug into this switch port will automatically be placed into this VLAN. Commonly used for devices which are not VLAN aware (most desktops/laptops).
- Tagged – if a device is VLAN aware and it has been assigned to a VLAN, when it is plugged into the switch port it won’t go into the Untagged VLAN, it will go into the Tagged VLAN (think IP phones)
As this switch is for my vSphere 5 environment and vSphere is VLAN aware. We are going to set every port to be Tagged into every VLAN. What will this achieve? Well every device which is not VLAN away will go straight into the Management VLAN. Then on the port group’s within the vSwitches I can assign VLAN’s.
To do this, click Network from the left hand menu, then VLAN and finally Modify Port
By default every port will be ‘untagged’ in VLAN 1 so we don’t need to make any modifications to this. Click Select All then Tagged and last of all Enter the VLAN ID’s in this case 10,20,30,40 and click Apply.
You will receive a pop up letting you know that Access Ports will change to Hybrid Ports, we are cool with this, so Click OK.
To verify the VLAN’s have been set correctly, go to Port Detail and choose Select All, it should show the following.
Assign An IP Address To Each VLAN
I mentioned earlier on in the post that we wanted to assign an IP address to each VLAN so that the HP v1910 24G becomes the default gateway for all devices. To do this select Network from the left hand menu, then VLAN interface and Create.
Now this is when I need to refer back to my network table! We input the VLAN ID e.g. 10 and then enter the IP Address e.g. 10.37.10.221 and Mask e.g. 255.255.255.0
I always deselect ‘Configure IPv6 Link Local Address’ then click Apply.
Rinse and repeat for the rest of your VLAN’s. To make sure everything is ‘tickety boo’ click on Summary and you should be greeted with a page similar to this.
Time to test. So from your computer you should now be able to ping each VLAN IP address on the switch.
Success, that’s our HP v1910 24G configured with VLAN’s.