IP Address Summarization

– 8+ subnets per site
– 3+ sites
– 500+ IPs per subnet
– 50+ Remote users (subnets within subnet) belonging to a site’s subnet
Note: our current LAN routes cannot easily be summarized. Therefore, I recommend that we keep our subnets within the subnet ranges of to so that it can be summarized as The break-down is as follows:
Summary Route: (Irvine) (Servers:, SAN: (Users) (Telecom) (Trusted) (Management) (Guest) (Isolation) (DMZ) => to (remote users: 64 subnets, each with 8 IPs)
Summary Route: (Phoenix) (Servers:, SAN: (Users) (Telecom) (Trusted) (Management) (Guest) (Isolation) (DMZ)
Summary Route: (Florida) (Servers: (Users) (Telecom) (Trusted) (Management) (Guest) (Isolation) (DMZ)
Summary Route: (Reserved)
Summary Route: (AWS) (A) (B) (C) (D)
SAN subnets should broadcast to as few IPs as possible. Thus, a mask of /28 with 16 possible IPs would highly optimize SAN traffic. This also enable us to have three entries on AWS route table as (local), (vgw-37fxxxx) and (igw-7d0exxxx).
How to summarize routes: https://learningnetwork.cisco.com/thread/23983
The easy way: http://www.netmatics.net/FreeTools/IPv4SupernetTools/SupernetCalc
Calculate IP address range from CIDR: http://www.ipaddressguide.com/cidr

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