The answer is yes, changing broadcast address to all ones won't kill

anything.

Thanks to:

Casper Dik <casper@holland.Sun.COM>

Singh Adrian <singha@aah.co.uk>

Frank Pardo <fpardo@tisny.com>

Frank Pardo's very detailed answer as well as the original questions are

following:

>Fromfpardo@tisny.com Wed Oct 15 22:39:38 1997

Date: Wed, 15 Oct 1997 09:34:55 -0400 (EDT)

From: Frank Pardo <fpardo@tisny.com>

To:tonywu@micro.life.nthu.edu.tw

Subject: Re: Broadcast address on 4.1.4 and solaris 2.x

> Fromsun-managers-relay@ra.mcs.anl.gov Wed Oct 15 04:44 EDT 1997

> Date: Wed, 15 Oct 1997 15:57:03 +0800 (CST)

> From: "Tony C. Wu" <tonywu@micro.life.nthu.edu.tw>

> X-Sender: tonywu@micro

> To:sun-managers@eecs.nwu.edu

> Subject: Broadcast address on 4.1.4 and solaris 2.x

> MIME-Version: 1.0

>

>

> Hello there,

>

> We have a mixed network of sparcs running both 4.1.4 and solaris 2.x

> They are on the same class C subnet. The last number of broadcast address

> on solaris 2.x is 255 (0xff), however, in sunos 4.1.4 it's 0 (0x00). And I

> just found a mysterious problem that sometimes solaris 2.x's network dies

> without any error messages. I believe it has something to do with the

> broadcast address, coz we have the same problem on a linux box which's

> connected to the same subnet and using 255 as the broadcast address too.

>

> So, Can we safely change SunOS 4.1.4's broadcast to 255 (0xff) without

> breaking any Sun's special services, such as NIS, some sort of RPC ?

> Can anybody explain why sunos 4.1.4 uses 0 (0x00) as the broadcast address

> ?

>

> Thanks,

>

> Tony C. Wu

>

The history: SunOS is based on BSD, and the original BSD implementation

of IP used all-zeroes for broadcasting. Solaris is based on SysV, which

used/uses all-ones for broadcasting.

What you should do: Configure all your SunOS machines to use all-ones.

All-ones is the standard nowadays; all-zeroes is obsolete.

Using all-ones on SunOS is perfectly safe. In several previous jobs, I

worked with mixed networks that included SunOS, and the SunOS machines

were always configured to use all-ones for broadcast addresses, to make

them compatible with Solaris, AIX, HP-UX, Linux, etc. Everything worked

just fine that way.

--
Frank Pardo <fpardo@tisny.com>
Transaction Information Systems
New York City

Chi fila ha una camicia e chi non fila ne ha due. -- Italian proverb

--
Tony C. Wu