SUMMARY: RIP vs OSPF

From: terzic@mda.ca
Date: Thu Aug 24 1995 - 08:34:28 CDT


Dear managers,

Thanks for all your help.
Basicly the question was about "variable-lenght subnets".
I'm going to implement "gated" public domain software that I got from:
        gated.cornell.edu:/pub/gated/

I joined mailing list:
        gated-people-request@gated.cornell.edu

                ***
Original question:
>
> As you know RIP (Routing Information Protocol) that comes with SunOS and
> Solaris has certain weaknesses:
> - RIP has no knowledge of subnet addressing
> - takes a long time to stabilize after a failure
> - maximum of 15 for the metrics etc ...
> We have CISCO 4500 router that supports OSPF and RIP.

> QUESTION:
> Can I mix these two protocols on the same physical network?
> Is there any Sun IP router that can do this (link subnets with different
> netmasks)?

Responses:
From: dhoward@worldlinx.com (David Howard)
        Want you are asking for is variable-length subnet masking - RIP
doesn't know how to do this, but OSPF and EIGRP do. (You will likely
be better off with EIGRP) This isn't a Sun issue at all - it's a
routing issue.

        What you do is take one of your subnets, and further subnet it.
 So, if you have the mask 255.255.252.0, your subnets are :

x.x.4.0
x.x.6.0
x.x.8.0

and so on...

take subnet x.x.4.0 and further divide it :

 255 255 252 0
1111 1111.1111 1111.1111 1100.0000 0000

 255 255 255 248
1111 1111.1111 1111.1111 1111.1111 1000

 Your first net work is

 x x 4 8
xxxx xxxx.xxxx xxxx.0000 0100.0000 1000

first host : 4 9
xxxx xxxx.xxxx xxxx.0000 0100.0000 1001

second host: 4 10
xxxx xxxx.xxxx xxxx.0000 0100.0000 1010

third host : 4 11
xxxx xxxx.xxxx xxxx.0000 0100.0000 1011

fourth host : 4 12
xxxx xxxx.xxxx xxxx.0000 0100.0000 1100

 etc.

broadcast: 4
xxxx xxxx.xxxx xxxx.0000 0100.0000 1111

next network is
                                  4 16
xxxx xxxx.xxxx xxxx.0000 0100.0001 0000

first host : 4 17
xxxx xxxx.xxxx xxxx.0000 0100.0001 0001

        etc.

extrapolate from there until you use up all 10 of the bits available to
you in subnet 4.0
==============

From: koen@ciminko.be (Koen Peeters)
In principle you can mix RIP and OSPF but you might end with unexpected
results.
Better is to use the gated deamon, which is a routing software that runs on
unix hosts and understands almost any routing protocol.

more info : http://gated.cornell.edu/
==============

From: Jas (Matthew K) <matt@uts.EDU.AU>
if you want to run OSPF get gated.
==============

From: tap116@nocc.minsy.navy.mil (Tom Plesha)
Yes you can mix two protocols on the same physical network. I don't know
what problem you are trying to solve, but you can "redistribute" OSPF to RIP.
That way RIP know everything that OSPF knows.
==============

From: kannan@catarina.usc.edu
> - RIP has no knowledge of subnet addressing

huh? That's not quite right, is it?

> - takes a long time to stabilize after a failure
> - maximum of 15 for the metrics etc ...

> QUESTION:
> Can I mix these two protocols on the same physical network?

You can do this, but it is not easy to do, very easy to screw up, very hard to
debug, and in general, very difficult to manage.

> Is there any Sun IP router that can do this (link subnets with different
> netmasks)?

sunos 4.* based machines do not understand variable subnet masks, and cannot
do this. Solaris based machines might.
==============

From: "Peter A. Starceski" <starcesk@noc.hfh.edu>
try gated software ... its public domain (I think Cornell University has it).
==============

Veselin Terzic | MacDonald Dettwiler
MIME accepted terzic@mda.ca | 13800 Commerce Parkway
Phone: (604) 278-3411 Fax: 278-3786| Richmond, B.C.;Canada V6V 2J3
include <disclaimers.h> | Key ID: 0xE24588D5 at keyservers



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:10:32 CDT