Date: Sat, 17 Mar 2001 23:35:16 -0800 From: "Ted Mittelstaedt" <tedm@toybox.placo.com> To: "Andrew Hesford" <ajh3@chmod.ath.cx>, "Michael Aucoin" <maucoin01@mediaone.net> Cc: "Doug Young" <dougy@gargoyle.apana.org.au>, "Rick Hamell" <hamellr@heorot.1nova.com>, "Jeff Soule" <jsoule@webcrossing.com>, <questions@FreeBSD.ORG> Subject: RE: Different Device Names for Identical NICs Message-ID: <007701c0af7d$f9f48ba0$1401a8c0@tedm.placo.com> In-Reply-To: <20010317123039.B41772@cec.wustl.edu>
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Hi Andrew, There are also some disadvantages of using different nic cards in a system, they are: 1) If you have a problem with one of the NIC's it's harder to troubleshoot. For example, suppose the network attached to one of the cards starts suffering a ton of deformed packets, well if both nics are the same you can simply switch interfaces with the network drop cables as well as switching IP numbers on the interfaces, then reboot and see if the problem follows the card or the network. While you can do this with different manufacturer's nic cards, it won't give you proof of a hardware failure being the culprit, because it could have just been an incompatibility between a particular hub and a particular card. 2) If you have decided on the absolute best card for your system, why sacrifice one of the interfaces? 3) There may be a possibility that the cards are incompatible with each other 4) You may find that the motherboard's BIOS will permit interrupt sharing on the 2 cards which may not occur on 2 dissimilar cards. Ted Mittelstaedt tedm@toybox.placo.com Author of: The FreeBSD Corporate Networker's Guide Book website: http://www.freebsd-corp-net-guide.com >-----Original Message----- >From: Andrew Hesford [mailto:ajh3@chmod.ath.cx] >Sent: Saturday, March 17, 2001 10:31 AM >To: Michael Aucoin >Cc: Doug Young; Rick Hamell; Ted Mittelstaedt; Jeff Soule; >questions@FreeBSD.ORG >Subject: Re: Different Device Names for Identical NICs > > >I don't know about two of the same network cards. It seems to me, that >for the sanity of the administrator, it would be wise just to buy two >cards that use different drivers. > >For one thing, one may forget what name is for what card, or how the >cards are connected to the network (was xl0 my outbound card, or my >inbound one?). > >In addition, as the drivers are revised, the order of recognition might >change, so one day xl0 might become xl1, and vice versa. A major >advantage of FreeBSD (indeed, any real UNIX) over Linux is that network >interfaces are named for their drivers and not eth*. This means I can >always distinguish two different cards, and my firewall rules will never >have to change because I upgraded my kernel. > >With Linux, on the other hand, the order of recognition of cards can be >flipped. I had this problem migrating from 2.2.x to 2.4.x, where my >D-Link DE-528 card (eth0 in 2.2.x) became eth1, and my Linksys became >eth0. All my firewall rules and configuration files had to be changed. >Now, I just have ed0 and dc0. > >By using two of the same card, or two cards that use the same driver, >you are inviting the same sort of trouble. > >On Sat, Mar 17, 2001 at 09:22:56AM -0500, Michael Aucoin wrote: >> All, >> >> Thanks very much for all the input. I thought I would give you an >> update. I was able to use both (3c509) NICs together after I rebuilt >> the kernel with ep1 (thanks, Rick). However, I was initially blocked by >> the NICs having the same IO address and IRQ. I reconfigured one of them >> (using the 3COM-supplied DOS utility) and all is well now. I have been >> brain dead about this whole thing, but I did not at first realize I >> would have to reconfigure the NIC. Is this usual? >> >> Mike >> >> >> To Unsubscribe: send mail to majordomo@FreeBSD.org >> with "unsubscribe freebsd-questions" in the body of the message >-- >Andrew Hesford >ajh3@chmod.ath.cx > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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