Date: Sat, 23 Aug 1997 14:38:13 +0200 From: j@uriah.heep.sax.de (J Wunsch) To: FreeBSD-hackers@FreeBSD.ORG (FreeBSD-hackers) Subject: Re: broadcast question Message-ID: <19970823143813.EY59755@uriah.heep.sax.de> In-Reply-To: <199708231004.MAA05509@gvr.gvr.org>; from Guido van Rooij on Aug 23, 1997 12:04:50 %2B0200 References: <199708231004.MAA05509@gvr.gvr.org>
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As Guido van Rooij wrote: > If I have a host in a subnetted C-net, say 192.1.1.0/28 > and I send an icmp echo request to the broadcast address of the C-net > (so NOT to 192.1.1.15) the 2.1.7 stack does send an echo reply > but the 2.2 stack does not. > So an all-subnets directed broadcast seems to be ignored on 2.2 > stacks...I think this broken, yet fail to see where it was broken. I think 2.1.x was broken. What is an ``all-subnets'' broadcast in a CIDR world? Forget about class A/B/C, forget the term `subnet', they don't exist anymore. (*) The address 192.1.1.255 is not in any way a valid broadcast address for net 192.1.1.0/28, it's a valid broadcast address for 192.1.1.128/25, or maybe for 192.1.1.240/28 (which are entirely different networks from 192.1.1.0/28). (*) The only meaning of the historic classes A/B/C that does still exist is that they determine the default netmask if nothing else has been specified in ifconfig(8), or route(8), etc. This can sometimes be convenient to type. 255.255.255.255 should work, i believe. I'm surprised 2.1.x was still broken in this respect. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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