From owner-freebsd-net Tue Feb 22 19:38:12 2000 Delivered-To: freebsd-net@freebsd.org Received: from ind.alcatel.com (postal.xylan.com [208.8.0.248]) by hub.freebsd.org (Postfix) with ESMTP id 9F14437B830 for ; Tue, 22 Feb 2000 19:38:08 -0800 (PST) (envelope-from wes@softweyr.com) Received: from mailhub.xylan.com (mailhub [198.206.181.70]) by ind.alcatel.com (8.9.3+Sun/8.9.1 (ind.alcatel.com 3.0 [OUT])) with SMTP id TAA07013; Tue, 22 Feb 2000 19:37:13 -0800 (PST) X-Origination-Site: Received: from omni.xylan.com by mailhub.xylan.com (SMI-8.6/SMI-SVR4 (mailhub 2.1 [HUB])) id TAA29116; Tue, 22 Feb 2000 19:37:12 -0800 Received: from softweyr.com (homer.softweyr.com [204.68.178.39]) by omni.xylan.com (8.9.3+Sun/8.9.1 (Xylan engr [SPOOL])) with ESMTP id TAA14570; Tue, 22 Feb 2000 19:37:09 -0800 (PST) Message-ID: <38B35790.EA9CADF@softweyr.com> Date: Tue, 22 Feb 2000 20:44:16 -0700 From: Wes Peters Organization: Softweyr LLC X-Mailer: Mozilla 4.7 [en] (X11; U; FreeBSD 3.3-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: Lloyd Rennie Cc: Wim Livens , Yusuf Goolamabbas , freebsd-net@freebsd.org Subject: Re: Understanding ifconfig output References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Lloyd Rennie wrote: > > On Mon, 21 Feb 2000, Wim Livens wrote: > > > On Mon, Feb 21, 2000 at 11:35:04AM -0000, Yusuf Goolamabbas wrote: > > > Here's some sample output from one of my machines (3.4-stable) which > > > has an Intel EEPro 100 attached to a Bay 350 switch > > > > > > fxp0: flags=8843 mtu 1500 > > > > > > ether 00:90:27:8d:49:7b > > > media: autoselect (100baseTX ) status: active > > ^^^^^^^^^^^^^^^^^^^^^^^ > > This is the info you want---^ > > > > I don't know what SIMPLEX means, I use the same card in 100Mb > > full-duplex and get similar output. > > Same here. The media autoselects FD, but still the simplex flag is set. > *shrug* They have completely different meanings. A quick look at the ifconfig source would tell you that. The 'flags=8843<...>' part of the output is the network interface options; IFF_SIMPLEX and friends are defined in /usr/include/net/if.h: ... #define IFF_ALLMULTI 0x200 /* receive all multicast packets */ #define IFF_OACTIVE 0x400 /* transmission in progress */ #define IFF_SIMPLEX 0x800 /* can't hear own transmissions */ #define IFF_LINK0 0x1000 /* per link layer defined bit */ ... As you can see, the IFF_SIMPLEX flags means this interface cannot hear it's own transmissions. Later, the media options are printed, showing you that your network interface card is configured for 100Base-TX full-duplex. > > What is the recommended way to determine link speed from a machine to > > a hub/switch. (e.g A colo provider claims that there is 100 Mbit card > > in the box and one would want to verify that) > > A fairly foolproof method is to make sure there's a fair amount of traffic > running in both directions, then do a 'netstat -I fxp0 -w1'. Watch the > collisions - if you see any then it's not FD. For the link speed, just look at the ifconfig output. If the interface is set to 100Base-TX and is working, it's in 100 Mbps mode. The only other option is 10Base-T. 100Base-TX full duplex is actually 200 Mbps - 100 each way. -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC wes@softweyr.com http://softweyr.com/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message