From owner-freebsd-tokenring Tue Apr 21 15:42:41 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA13752 for freebsd-tokenring-outgoing; Tue, 21 Apr 1998 15:42:41 -0700 (PDT) (envelope-from owner-freebsd-tokenring@FreeBSD.ORG) Received: from charon.ccnvhi.com (wkstn.ccnvhi.com [207.247.3.162] (may be forged)) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id WAA13738 for ; Tue, 21 Apr 1998 22:42:25 GMT (envelope-from pnorton@ccnvhi.com) Received: by charon.ccnvhi.com; (5.65v3.2/1.3/10May95) id AA00010; Tue, 21 Apr 1998 15:42:23 -0700 Date: Tue, 21 Apr 1998 15:42:17 -0700 Message-Id: <199804212242.PAA00550@grumpy.ccnvhi.com> From: Paul Norton Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: "Larry S. Lile" Cc: Paul Norton , tokenring@FreeBSD.ORG Subject: Re: Current work... In-Reply-To: References: <199804212055.NAA01835@grumpy.ccnvhi.com> X-Mailer: VM 6.22 under 19.15 XEmacs Lucid Sender: owner-freebsd-tokenring@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Larry S. Lile writes: > All the AIX boxen I admin run a MTU of 1492 on their token ring interfaces, > any clue at to the 8 byte diff? Were basically going to need a > /usr/src/sys/net/iso88025.h which would contain: 1492 is the MTU for Ethernet II(??), I believe, but I'd have to go back and reference Stevens to be sure. Are you in a bridged environment? > #define ISO88025_TYPE_LEN 2 /* Assumed */ > #define ISO88025_CRC_LEN 4 /* Assumed */ You'll never see the TR MAC CRC. It is stripped from the frame before the driver gets it. > #define ISO88025_HDR_LEN (ISO88025_ADDR_LEN*2+ISO88025_LEN) /* +RIF? */ > #define ISO88025_MIN_LEN x /* No clue */ 802.5 can have a zero-length payload. > #define ISO88025_MAX_LEN 1518 /* Assumed same as ethernet */ 17,960 for total frame size at 16 Mbps. > #define ISO88025_IS_VALID_LEN(foo) \ > ((foo) >= ISO88025_MIN_LEN && (foo) <= ISO88025_MAX_LEN) This should be determined by the driver after initialization. If the adapter has 8K shared-RAM configured, you'll only be able to support about a 3K MTU. If they have 64K configured the MTU can go to 17K. At any rate you will only be able to determine this after the driver/adapter has initialized. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-tokenring" in the body of the message