It’s a common frustration in the IT world. What may you ask? Well, that would be load balancing for network traffic. As more traffic pours into a network, the harder it must work to allocate or distribute said traffic across varied server centers or farms. We would all love for our networks never to experience down moments or offer a lagging experience to our customers, so how can we make sure we are properly handling the load balance when configuring our EIGRP for unequal cost paths, which is where control and order by an EIGRP is needed.
What Are the Two Types of Load Balancing?
Generally speaking, load balancing is a router’s capability to properly distribute network traffic across all of the router network ports that share equal distances from their targeted address. This optimizes how the network segments are utilized, increasing effectiveness of network bandwidth. Currently, there are considered to be two types of load balancing, equal and unequal cost paths. Let’s see what the differences are between the two:
Cost Path: Equal is a type of load balancing comes into play when there are two or more different paths to the same destination network reporting similar routing metric values. Your maximum-path command will determine the total number of routes your routing protocol can use. Cost Path: Unequal load balancing is the same as an equal cost path except the routing metric values are not the same. You can use a variance command when you configure eigrp to set how the router will route the incoming network traffic.
How to Configure for Correct Load Balancing
First, you’ll want to enable EIGRP, so you will need to run the proper command: Router(config)# router eigrp [ASN]. From here you will add a network to your EIGRP. This will form EIGRO adjacencies from non-passive interfaces on the selected network. The interface can also be set to a passive operation to stop EIGRP advertisement. Now you will want to disable your automatic classful summarization to prevent looping route queries. Now it is time to configure for load balancing: EIGRP automatically balances load balances across equal-cost links. Although unequal cost links are not automatically configured, you can manually enable this feature and set a determined variance: Router(config-router)# variance [multiplier]
You can set variances anywhere between 1 and 128 with 1 being the default and only used for equal cost balancing. Now we will want to perform some fine-tuning to our EIGRP timers. Although adjacencies can be made without timers matching from two routers, you can manipulate the metrics of your EIGRP in order to optimize network performance. Using K-values, you can manipulate metrical values with each value being assigned as follows:
The default command is for bandwidth and delay, and then the following values are Ks: Router(config-router)# metric weights 0 1 1 1 1 1. From here you will authenticate, manipulate the bandwidth, monitor and tweak as needed until your load balancing is at optimal performance for the network traffic.
Configuring EIGRP is fairly cut-n-dry, however in complexed situations when EIGRP quits, it ends up putting detrimental loads that are impossible for the router and firewall to handle. Ensuring your network is optimized may need outsourcing or some type of IT Ops Virtual Assistant to overlook and test the network to ensure everything is running as it should, and your traffic continues without ever noticing a hiccup.