From owner-freebsd-net Tue Jun 15 20:51:56 1999 Delivered-To: freebsd-net@freebsd.org Received: from mail-out1.apple.com (mail-out1.apple.com [17.254.0.52]) by hub.freebsd.org (Postfix) with ESMTP id C172E153AA for ; Tue, 15 Jun 1999 20:51:54 -0700 (PDT) (envelope-from justin@walker3.apple.com) Received: from mailgate2.apple.com ([17.129.100.225]) by mail-out1.apple.com (8.8.5/8.8.5) with ESMTP id UAA22468 for ; Tue, 15 Jun 1999 20:51:54 -0700 Received: from scv3.apple.com (scv3.apple.com) by mailgate2.apple.com (mailgate2.apple.com- SMTPRS 2.0.15) with ESMTP id for ; Tue, 15 Jun 1999 20:51:47 -0700 Received: from walker3.apple.com (walker3.apple.com [17.219.24.201]) by scv3.apple.com (8.9.3/8.9.3) with ESMTP id UAA15080 for ; Tue, 15 Jun 1999 20:51:44 -0700 Received: by walker3.apple.com (8.9.1/8.9.1) id UAA00707 for freebsd-net@FreeBSD.ORG; Tue, 15 Jun 1999 20:51:40 -0700 (PDT) Message-Id: <199906160351.UAA00707@walker3.apple.com> To: freebsd-net@freebsd.org Subject: Re: Multiple ethernet frames for IPX In-Reply-To: <199906160120.SAA00645@walker3.apple.com> Date: Tue, 15 Jun 1999 20:51:33 -0700 From: "Justin C. Walker" Reply-To: justin@apple.com X-Mailer: by Apple MailViewer (2.105.dev) Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Boris, Thanks for the response; I have a few more questions: > From: Boris Popov > Date: 1999-06-15 19:28:08 -0700 > To: "Justin C. Walker" > Subject: Re: Multiple ethernet frames for IPX > Cc: freebsd-net@FreeBSD.ORG > In-reply-to: <199906160120.SAA00645@walker3.apple.com> > > On Tue, 15 Jun 1999, Justin C. Walker wrote: > > > > Yes, it is really works now. This is first public release of > > > if_ef driver which extends current functionality of existing ethernet > > > drivers. > > > > I have a couple of questions: > > > > How does this handle the problem of getting a forwarded packet back > > into the wrapper it needs (e.g., 802.3/SNAP)? > > Packet sended/forwarded to interface. Since frame type > determined from the interface it is not a problem for ether_output() > rotine to select appropriate frame to wrap in. I should be clearer. What I meant to ask is: given that you have a packet in the routing layer to forward, and that its incoming framing has been stripped, how does the routing layer decide what framing (E-II, 802.3/SNAP, ..) to use when sending it? > > Why is this better than, e.g., having stacks register for > > packet-type reception? I'd think this would perform better than the > > "virtual device" scheme. A (minor?) drawback is updating both stack > > and "driver family support" (e.g., ether_input()) to handle this. > > No, you will also need to rewrite route* procedures. And changes > required to protocol stack(s) aren't "minor" in this case. I don't understand this. If the route* procedures need rewriting in this case, why not in the "virtual device" case? Also, I don't see why the stack changes are a big deal. For each configured interface, the stack has to "register", which can be handled in the same "piece" of the stack that deals, e.g., with ARP and addressing issues. I'm trying to get a better handle on the issues, since we're trying to deal with this at Apple now. Thanks, Justin -- Justin C. Walker, Curmudgeon-At-Large * Institute for General Semantics | Manager, CoreOS Networking | When crypto is outlawed, Apple Computer, Inc. | Only outlaws will have crypto. 2 Infinite Loop | Cupertino, CA 95014 | *-------------------------------------*-------------------------------* To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message