Date: Thu, 15 Aug 96 11:08:00 PDT From: Robert Clark <ROBERTC@PII.COM> To: "'freebsd-questions'" <freebsd-questions@FreeBSD.ORG> Subject: FW: Two Ethernet cards in one machine on same IP network Message-ID: <3213679A@smtp>
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If I put myself in this scenario, why would I want more than one card on the same wire? One card for normal uses, one to act as a diagnostic tool? Two cards because one can't handle a saturated network? (Probably not a valid reason.) Two cards, because there are actually two distinct nets on the same wire. (Probably not a valid situation.) Could this be done with aliases instead? Even with different classes of networks? Two cards, because someone wants to setup a proxy or socks system? I use a proxy system, but with one card only. [RC] robert.clark@pii.com On Wed, 14 Aug 1996, Michael Ryan wrote: > I've a system (FreeBSD 2.1R) with two NICs: WD8013 and NE2000. > I want to plug both of them into the same IP network, > on the same cable. No can do!!! I don't have any intimate knowledge of the implementation of IP in FreeBSD, but the first (well, O.K. among the first) thing I learned about IP is that a machine MUST have at most one interface on an IP network. That's part of the reason subnetting was invented! I can't imagine why you'd like two cards on the same ethernet cable, but if you really do, give one of them a netmask of 255.255.255.255. This would cause it to be used just to receive packets for its address (I think it will never transmit. Am I wrong on that???). > > I ifconfig the WD8013 (ed0) first, and it goes fine. > When I ifconfig the NE2000 (ed1), I get an error message > as follows. > > # cat /etc/hosts > 194.9.12.7 h1 > 194.9.12.8 h2 > # ifconfig ed0 inet h1 > # ifconfig ed1 inet h2 > ifconfig: ioctl (SIOCAIFADDR): File exists It's telling you that you already have an interface to that network. > > When I then do "ifconfig ed1" the parameters (IP address, > netmask and broadcast address) are fine, but I can't ping > the IP address (h2), even from the machine itself. The Because the ifconfig failed. > routing table shows that the address (194.9.12.8) is reached > via link#1 -- which is sort of correct, as that's the > interface to the 194.9.12.0 network, but that's not what > I expected (link#1 == ed0). > > Any ideas? > > > Thanks, > Mike > <mike@NetworX.ie> > --- > > > > You're welcome, Nadav
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