From owner-freebsd-net Thu Aug 19 11:50: 8 1999 Delivered-To: freebsd-net@freebsd.org Received: from inet-vrs-02.microsoft.com (mail2.microsoft.com [131.107.3.124]) by hub.freebsd.org (Postfix) with SMTP id D61C81521E for ; Thu, 19 Aug 1999 11:50:00 -0700 (PDT) (envelope-from gchung@microsoft.com) Received: from 157.54.9.104 by inet-vrs-02.microsoft.com (InterScan E-Mail VirusWall NT); Thu, 19 Aug 1999 11:48:45 -0700 (Pacific Daylight Time) Received: by INET-IMC-02 with Internet Mail Service (5.5.2448.0) id ; Thu, 19 Aug 1999 11:48:45 -0700 Message-ID: From: George Chung To: George Chung , "'freebsd-net@freebsd.org'" Subject: RE: PLEASE HELP: mcast weirdness on private network Date: Thu, 19 Aug 1999 11:48:36 -0700 X-Mailer: Internet Mail Service (5.5.2448.0) Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org BTW, there is no problem when using the all-hosts address 224.0.0.1. > -----Original Message----- > From: George Chung > Sent: Thursday, August 19, 1999 10:25 AM > To: 'freebsd-net@freebsd.org' > Subject: PLEASE HELP: mcast weirdness on private network > > Hi Gurus: > On a "normal" network (routers, connected to the inet), an app on NT4 and > FreeBSD 3.2 can join an mcast group (225.0.0.1) and send/receive messages > to each other on that address. > > However, when I move the binaries to a private network (no router) with > NT4 and FreeBSD: > An NT box is able to communicate bidrectionally with another NT box. > The FreeBSD boxes are able to communicate bidrectionally with each other. > The FreeBSD boxes are able to receive mcast packets from the NT boxes. > BUT, the NT boxes aren't able to pick up mcast packets from FreeBSD!! > > Here's the network: > m1 10.100.100.100 FreeBSD dual-homed (the 2nd interface is unconfigured). > m2 10.100.100.102 FreeBSD dual-homed (the 2nd interface is unconfigured). > m3 10.100.100.200 NT4 > m4 10.100.100.202 W2K > > I had to tweak the FreeBSD boxes to get them to even work by adding a > route for 225.0.0.1 (otherwise, I got a EHOSTUNREACH error when pinging > 225.0.0.1). I am not sure I did this correctly. Here's my command: > > route add -net 225.0.0.1 -netmask 0xf0000000 -interface 10.100.100.100 > > The mcast code on FreeBSD does the following above and beyond the default > (because they are multihomed): > in the call to join the group, I specify the specific interface to receive > on. > I also call setsockopt to set the outgoing interface on mcast sends. > > I am scratching my head. The only thing I can think of is that Windows NT > is filtering out IP packets whose source IP address it doesn't "know". But > the only way I know how to do that for UDP sockets is to explicitly > connect it to an endpoint. Any help would be greatly appreciated. > > Thanks, > George > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message