Basic Guide For The Barracuda Link Balancer

This is a basic guide for the Barracuda Link Balancer. The Barracuda Link Balancer is a comprehensive device that dynamically balances and manages traffic across multiple Internet links. This guide will look at how to navigate your way round the graphical user interface of the box and some of the useful features contained within.


Main Status Page

When you first log into the device, you are greeted with the main status page. Highlighting each of the main tabs at the top brings up a series of sub menus below that tab.


The main status page is populated with graphs and status indicators that can give you a good general idea of how the Internet connections are performing:

Links (Utilisation) – These bars indicate how much of the available bandwidth for each named link is currently being used.

Subscription Status – A handy quick reminder each time you log in of when the subscriptions for this particular device expire. If you have recently updated or upgraded your subscription(s), hitting the refresh button should bring everything up to date.

Performance Statistics – This bank of information is an easily referenced summary of how the device is performing. Particularly useful if you think the device might be overheating or running close to resource capacity.

Utilisation Graphs – These graphs indicate the inbound and outbound traffic levels, in KB, for each named link and can be interrogated by hour, day or month.



Checking and configuring the Links area

The Links menu is used to manage the individual Internet links that connect to your device, and can be reached either by clicking on one of the links in the Links (Utilization) section of the main page or by navigating to the Basic > Links submenu.

From the front Links page, you can see each of the Internet connections has its own line and you can check to see whether each connection is up and functioning, what IP address it is using, and whether it is defined as a Primary or Secondary link.

By clicking the + symbol next to each of the connections you can expand the settings for each one and also configure these settings. The fields here are pretty self explanatory, with handy dialogue boxes next to most of them explaining their function. Make sure the upstream and downstream figures are correct for that particular connection – speak to your ISP if you are unsure. Always make sure that your subnets are correct.


The bottom section can be used to test the functionality of that particular connection. You can run PING or DNS tests here which should help determine if the link is working as it should be.


Configuring and locking down access to your device

You should make sure that your device only allows administrative access to the correct and expected individuals. This is configured under the Basic > Administration menu.

Set the password for your device in the Password Change section. Always ensure that your password is secure – if in doubt refer to our Secure Passwords guide. The username for the device will always be “admin”.

The Administrator IP/Range section enables you to lock down access to the device to specific IP addresses, both internally and externally, which is always a very good idea. If your device is managed by ourselves, then this section will most likely contain the IP addresses of our network administrators. You should also allow access to the device from a couple of devices on your internal network, in case an engineer needs to access the device from the LAN side in an emergency or are performing network configurations on site. Be aware of the fact that if you don’t define anything in this section, and Administration Access is set to On, then any device either externally or internally will be able to reach to your Link Balancer if they have the relevant IP information.

Administration Access Control is where you can limit access to the admin GUI via particular links, so if you only want the access to be available to one of the WAN link IP addresses, select the relevant connection in this box.


Configuring the Link Balancer to provide DHCP to your network

The Barracuda Link Balancer can be used as a DHCP server and provide your network with IP address from a predetermined range. Access these settings within the Services > DHCP Server submenu.

Again this section is quite self explanatory, as long as you are a little familiar with DHCP generally. If you are unsure as to the syntax of each field, handy dialogue boxes are provided next to each one to keep you informed.


Define the parameters of each DHCP scope range in the top section. By clicking the Add box in the top right, this will add the range to the DHCP Server Subnets section, which lists all of the available ranges the device is configured to use for DHCP.

The Active Dynamic Leases section at the bottom gives you live data on what IP addresses are currently in use by which MAC addresses. If you are having problems with a particular device and want to kick it off the network, you can hit the Release button next to any of the entries to boot them off temporarily (though they will be assigned another address).


Checking for any potential problems

The Link Balancer can be used to help troubleshoot any problems you may be having on your network, both on the LAN side and the WAN side. If you are experiencing problems in either of these areas, you should have a read of our helpful troubleshooting guides here and here.

Navigating to the Logs menu will give you 3 submenus – Event Log, Firewall Log, and VPN Log.


Locating the source of problems is always a tricky business, especially when you are combing through long lists of log files that contain a lot of (sometimes irrelevant) information. The activereach support team or the Barracuda Support Desk can be very helpful in helping to decode what the logs mean, and you can get the Barracuda Support Team directly involved by giving them a connection to the logs – this is done under the Advanced > Troubleshooting menu, but always speak to them first before going down this path.

The best approach is always to familiarise yourself with the logs in a working, resting state. This means you will get used to seeing the log entries you are “supposed” to see so that when you are looking for a problem, the irregular entries are more obvious.

If you are completely stumped or just want some general advice, then as a customer you can export the logs into a CSV file and send them to us, or provide us with direct access to the device