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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