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IP addressing scheme

Jonathan Axford
Trusted Contributor

IP addressing scheme

Hi Guys,

Need a bit of a sanity check on a new IP scheme that is being introduced into a network, as a basic overview i have written down all of the IP ranges and on what routers they will sit on, if you fancy having a quick look over it feel free!

Cheers

Here is the basic layout, there are a number of VLANs on each router with the following subnets associated with them. The routing protocol will be ospf.

Layout :

Router2-------Router1---------Router3

Router 1 VLANS:
172.16.1.0/24
172.19.0.0/16
172.16.12.0/22
172.17.0.0/20
172.18.0.0/20

Router 2 VLANS:
172.16.2.0/24
172.16.16.0/22
172.17.16.0/20
172.18.16.0/20

Router 3 VLANS:
172.16.3.0/24
172.16.20.0/22
172.17.32.0/20
172.18.32.0/20

Does this look like it would be ok? The reason for the scheme is that the client was (Unknowingly) using non rfc1918 compliant addresses as internal private addresses and wanted to conform to best practice by only using rfc1918 compliant addresses, so we have had to chop the 172.16-172.32 range up a bit...

Cheers

Where there is a will there is a way...
3 REPLIES
Jonathan Axford
Trusted Contributor

Re: IP addressing scheme

One thing that is niggling me is that it doesn't follow OSPF best practice in the sense of keeping contiguous networks together, I.e using a Hierarchical design...
Where there is a will there is a way...
Mohieddin Kharnoub
Honored Contributor

Re: IP addressing scheme

Hi Jonathan

Nice IP Addresses setup :)

For the OSPF contiguous networks, its useful to summarize the addresses out of any router.

I think you may find a happy time trying to do this :), but i checked it up, and i think you don't have any overlapping.

Good Luck !!!
Science for Everyone
Jonathan Axford
Trusted Contributor

Re: IP addressing scheme

Hi,

Just after i made the post, i went back to the drawing board and changed in to contigous networks! I knew i had missed something.

Now, each building has its own class B which is then subnetted up further..

I.e

Building 1
172.23.1.0/24
172.23.4.0/22
172.23.48.0/20

Building 2
172.24.1.0/24
172.24.4.0/22
172.24.48.0/20

I think it will make for much neater routing tables and also makes it less confusing for the guys supporting it...

Cheers
Where there is a will there is a way...