switches

Is your data network ready for VoIP?

Hi folks! One of the greatest things about today’s network is that it seems to be able to handle anything. It doesn’t seem to matter what you want to do on your network, there is always a technology around the corner that can make it happen for you.

Well one of the most common things happening today is the conversion of data networks to voice and data networks. With the coming of VoIP, network engineers have been put under an increasing burden to support the world of the telephone when historically data and voice have been two separate entities.

There are a lot of people that erroneously think that VoIP is all about the phones and the PBX, but in reality if you don’t have a data network that can handle the traffic, none of that is really going to matter. Some of things network administrators find out in the end is that a switch isn’t always just a switch. What I mean by this is that administrators have been forced to cut and slash budgets and buy cheaper equipment only to find out that their switch is sub-par and cannot support a voice network. They are then faced with redoing their entire data network infrastructure which makes the cost of going to VoIP prohibitively expensive.

If administrators really look at what is offered to them when they buy network equipment such as switches, they can then plan for future VoIP deployments so when the time comes their data network will be ready. Things such as QOS and POE are two items that are not paid heed to when buying switches if VoIP isn’t in the equation, but then you find out you need it when the company starts going in the VoIP direction.

What I’m trying to say here is that in the future, almost all of us will be using VoIP, so you might as well start planning for getting your data networks ready now.

-RP

VTP - should you use it?

Hi folks! So welcome to the wonderful world of networking! You buy that fancy brand new Cisco switch and you think to yourself, “I have this cool feature called VTP (Vlan Trunking Protocol) and I want to use it to automatically deploy vlans across all of my switches! This will save me tons of configuration time!” Well should you really do this? Here are my thoughts on the matter.

It seems there are two schools of thought to this. VTP is a great protocol for quickly configuring switches, it takes the monotony out of configuring switches with tons of vlans. On the otherside, VTP is easily taken advantage of. If your network is not properly secured an attacker could easily use VTP to compromise your network!

So this is what I would recommend, don’t use it unless you absolutely have to. Even if you do end up using it then remember to lock down your switch using best practices. Turn off all unnecessary trunk ports, and enable port security where possible. Also even if you use a password with VTP it has been proven that there are methods to retrieve this password.

-RP

More Cisco gear for the SMB world!

Hello again folks! Cisco is once again bringing great product to the market place. This time hitting the SMB market with a new series of switches called the Cisco ESW 500 series.

These switches are all manageable from GUI utilities without the need for CLI. They are also priced at a great price point for your SMB customers. A lot of times when I go into SMB clients the perception is that Cisco is expensive and they instead vote to go with a different company for their switching gear. Cisco has seen the light and is now offering cheaper product in this marketspace.

The ESW 500 series is available with gigabit capability and even POE! This makes it great for the SMB company that wants to implement VOIP and reap those benefits. Cisco needs to keep releasing SMB product like this, it really will make all the others stand up and take notice! You can read more about it here.

-RP

Aggregating links on Cisco switches

Hello again folks! So you’ve just recently got your purchase approved for a brand new set of switches and you want to find a way to increase your throughput. What do you do? You aggregate links of course!

Aggregating links is a common thing done on high end switches such as Cisco or HP switches to name a few. The idea behind it is to take two or more ports and bind them together to create a single virtual port that connects to another switch. Then you can take your traffic and shuttle it over this link.

In Cisco land this is called Etherchannel. When you create an Etherchannel, it is treated like an interface. People will commonly create Etherchannels and then trunk their vlans across this link. This allows for quite a bit of bandwidth, especially on gigabit switches. This doesn’t double your bandwidth but it does increase it by a fair bit.

You can read more about etherchannel here.

-RP

Extended vlans in Cisco switches

For those of you venturing into switching for the first time, one of the things that can be hard to wrap your head around if you’re just a beginner is vlans. Vlans are great ways to make the management of your network a lot more organized, and are used everywhere in this world. You’re not going to be able to enter the switching world without running into them so it’s best to learn about them asap.

Now one of the things that can cause you troubles down the road is configuring vlans across many switches in large environments. This is made easier by the use of VTP (VLAN Trunking Protocol). You can use this to automatically configure vlans across many switches.

Unfortunately you might run into a problem when using extended vlans. If you use extended vlans and VTP version 2, you will find that you can’t use vlans all the way up to 4095. Instead what you need to do is use VTP version 3 which will enable you to use the entire range, or you can put your switch in VTP transparent mode to allow it to use extended vlans.