Re: [Phpip-support] Understanding CIDR entries and Prefixes
Brought to you by:
trilexcom
Menu
▾
▴
Re: [Phpip-support] Understanding CIDR entries and Prefixes
|
From: <php...@li...> - 2006-10-26 19:24:50
|
Thank you for your prompt response. See additional questions/comments below. Best regards, JD=20 -----Original Message----- From: Michael Earls [mailto:mi...@mi...]=20 Sent: Wednesday, October 25, 2006 10:57 PM To: Dean, John; php...@li... Subject: RE: Understanding CIDR entries and Prefixes=20 Hi John, To answer your question regarding VLSM and CIDR, the difference is that with VLSM, the recursion is performed on the address space previously assigned to an organization and is invisible to the global Internet. CIDR, on the other hand, permits the recursive allocation of an address block by an Internet Registry to a high-level ISP, to a mid-level ISP, to a low-level ISP, and finally to a private organization's network =20 They way phpip will use CIDR is to define the address block and then build the networks within that address block. You can also apply group based control over each CIDR block for administration. CIDR blocks that are less then /24 will build multiple /24 (256) for easy IP administration.=20 Examples; CIDR block 10.0.0.0/16 -- Building A 10.0.1.0/24 1st Floor East 10.0.2.0/24 1st Floor West 10.0.3.0/24 2nd Floor East OR CIDR block 64.50.56.32/28 -- ISP 1 64.50.56.32 network 64.50.56.33 router 64.50.56.34 host1 To answer you question from below on how to build the following networks. CIDR block 10.0.0.0/24 (256 ip's) PREFIX =3D> 10.0.0.0/24 >>>>>comment<<<<< As previously mentioned entering this CIDR returns a page with 65,535 prefixes each with it's own check box. =20 This makes the returned html page hard to manipulate because it takes MANY minutes to load. Do these prefixes remain in the database somewhere? And does that even matter? If I wanted to really add all these entries, would I have to check 65,335 boxes? :-( Will I have to load this entire page every time I want to activate a new /24 in the 10.0.0.0 range? Maybe this is just the way it is but I wonder if there could be options to either: (a) enter the number of prefixes to generate (or display for selection) starting from the base entry (a zero entry means generate/display ALL which is the current behavior) E.g. 10.0.0.0/24 qty 2 would generate/display prefixes 10.0.0 - 10.0.1 10.100.50.0/24 qty 4 would generate/display 10.100.50 - 10.100.51 - 10.100.52 - 10.100.53 (b) <page> the output to make it easier to manipulate (c) create an option to check/uncheck all checkboxes on the page (for unavoidably long pages) (d) create an option to add a prefix directly (without having to select from the CIDR entries) >>>>>end<<<<< CIDR block 10.0.2.0/23 (512 ip's) PREFIX =3D> 10.0.2.0/24 PREFIX =3D> 10.0.3.0/24 >>>>comment<<<< returns almost as much data as first entry, and as every entry is a /24 it essentially repeats the work of the previous entry - the same is true for all the following entries below. >>>>end<<<< CIDR block 10.0.4.0/22 (1024 ip's) PREFIX =3D> 10.0.4.0/24 PREFIX =3D> 10.0.5.0/24 PREFIX =3D> 10.0.6.0/24 PREFIX =3D> 10.0.7.0/24 ... CIDR block 10.0.8.0/21 (2046 ip's) PREFIX =3D> 10.0.8.0/24 PREFIX =3D> 10.0.9.0/24 PREFIX =3D> 10.0.10.0/24 PREFIX =3D> 10.0.11.0/24 ... CIDR block 10.0.16.0/20 (4094 ip's') PREFIX =3D> 10.0.16.0/24 PREFIX =3D> 10.0.17.0/24 PREFIX =3D> 10.0.18.0/24 PREFIX =3D> 10.0.19.0/24 ... Does this answer your question? Thanks, Michael Michael Earls http://www.vermeer.org <http://www.vermeer.org/> http://www.vermeer.org/pgp http://www.phpip.net <http://www.phpip.net/>=20 PGP Info: KeyID 0x168CBA4E Fingerprint 14DD 0899 8FE4 1C16 9561 FA2A 1ACB CA91 168C BA4E =20 ________________________________ From: Dean, John [mailto:joh...@me...] Sent: Wednesday, October 25, 2006 1:44 PM To: php...@li... Subject: Understanding CIDR entries and Prefixes=20 I have some questions about Phpip that are not really addressed in the documentation.=20 Hopefully you can point me in the right direction or to a user forum or something like that.=20 I am having trouble understanding how the CIDR entries and the Prefix entries relate to each other. I wonder if my problem stems from the fact that our network is really constructed as VLSM not CIDR and perhaps I do not understand CIDR well enough... I know that if I create a CIDR entry for 10.0.0.0/8, Phpip generates one Prefix -- 10.0.0=20 If I create 10.0.0.0/16 Phpip generate 256 Prefixes -- 10.0.0 through 10.255.0=20 If I create 10.0.0.0/24 Phpip generates 65535 Prefixes -- 10.0.0.0 through 10.255.255.0=20 As far as I can tell all these entries go into the DB, and as you might expect some of them they make the prefix related dynamic web pages extremely LARGE and difficult to deal with. Let's say the following five sub networks make up the entirety of my network - how do I get this network described in Phpip? What CIDR entries must I create in in order to generate the five (and only five) correct prefixes and associated ip address pools? 10.0.0.0/24 (256 ip's)=20 10.0.2.0/23 (512 ip's)=20 10.0.4.0/22 (1024 ip's)=20 10.0.8.0/21 (2046 ip's)=20 10.0.16.0/20 (4094 ip's')=20 This isn't really how my network is constructed, but I think the explanation of this example will help me understand how this works. Thanks in advance.=20 JD=20 |
