Eigrp summary route calculator how to#
Eigrp summary route calculator manual#

Network 8.8.8.0/23 can be used to summarize all four network behind R2. Create your summarized network, which is composed using the results from steps 3 and 4:ģ. Count all bits where both IPs match to determine the subnet mask:ĥ. Determine up to which point the two IPs match and convert to decimal, considering the remaining bits to the right equal zero, X=0:Ĥ. Convert to binary the octet where the IPs start to differ.ģ. Identify the network with the highest and lowest IP addresses, 8.8.8.32/28 and 8.8.8.0/28 on R1.Ģ. To determine a summary route, use the following procedure:ġ. R1 will locally determine which interface to use to route the packet. With route summarization, R2 only needs to have a summary route to reach all R1′s stub networks. Without route summarization, R2 has to have specific routes in its routing table to reach the three stub networks connected to R1.

Eigrp summary route calculator manual#

Routing protocols can summarize the addresses of several networks into one address, so we need to do proper manual summarization for specific information about that network, as we have done for the following example. If you don’t convert this then you have no way of knowing if you are advertising the correct summary route, which will lead to problems on your network.

You can only really work out a summary route by converting the IP address into binary.

This means that you can’t randomly assign networks to various routers or LANs within your network.įrom the above table, you can understand that the network id will be 172.16.8.0 with subnet mask255.255.248.0 (subnet mask at /21). You also need to design your network in a hierarchical order, which will require careful planning and design. In order to use route summarization on your network, you need to use a classless protocol, such as RIPv2, EIGRP, or OSPF.

Eigrp summary route calculator how to#

So make a cup of coffee or tea and concentrate for some time to understand how to use the route summarization technique in your network. Route summarization is also known as supernetting and was proposed in RFC 1338, which you can read online by clicking on the RFC. If these routes all had to be stored individually, the internet would have come to a stop many years ago. There are many millions of routes on the internet. In a few simple words, route summarization is a method for consolidating a group of networks into a single network with the main objective of reducing the routing table size and complexity. In this article we are going to discuss route summarization, the article most awaited and demanded by my regular readers.