Dual NIC Cards

karlp at ourldsfamily.com karlp at ourldsfamily.com
Fri Apr 14 18:15:43 UTC 2006 

On Fri, April 14, 2006 12:02 pm, Rick Stevens said:
> On Thu, 2006-04-13 at 23:18 -0600, karlp at ourldsfamily.com wrote:
>> On Thu, April 13, 2006 10:41 pm, Bret Stern said:
>> >
>> > I have dual network cards in a new box
>> > i'm putting together. Fedora 4
>>
>> Me, too.
>
> I have machines with up to 6.

Bragger...

>
>> > Both cards are set to activate on boot, but
>> > only one starts on boot. The other will start
>> > manually.
>>
>> Mine both start on boot.
>>
>> >
>> > One card has a static ip.
>> > One card gets assigned an ip address (dhcp)
>>
>> I assigned static IPs to both. That may be why one of yours doesn't start.
>> Is the one that starts the static or DHCP assigned nic?
>>
>> >
>> > Can both cards have the same hostname?
>> > (go ahead have fun with that question)
>>
>> They have to have the same hostname. I don't see an option in the gui
>> setup
>> to give a different hostname for each card.
>
> Ah, fertile ground for misunderstandings.  You must keep in mind that
> there are differences between hostnames, nodenames and FQDNs (fully
> qualified domain names).
>
> A machine can only have one hostname (as displayed by "hostname" or
> "uname -n"), and is the true hostname.  By default, it's "localhost" or
> the FQDN "localhost.localdomain".
>
> A machine _may_ have a nodename under NIS/NIS+ and is set and displayed
> by the "domainname" command.  Unless you run NIS/NIS+, you needn't worry
> about this, and if you do run it, 95 times out of 100 you'll set it to
> be the same as the hostname.
>
> Now, each IP address on the machine _may_ have a FQDN associated with
> it, but it's not required.  Each FQDN can have a number of DNS aliases
> associated with it (called CNAMEs in DNS parlance).
>
> Confused yet?

I'm not, but then I've done this though no where near as well, or as much,
as you. That's why I left my original response short. I'm leaning on you...

>
>> > I've heard you can only have a gateway address
>> > on one nic card. Is this correct?
>>
>> Yes, it's correct.
>
> Uhm, this must be clarified.  There is only one _default_ gateway, and
> that is the "route of last resort".  In other words, if you try to send
> traffic to a node that is not on a network directly connected to one of
> your NICs (as determined by the IP address/netmask combination) AND you
> don't have a route forcing traffic for the remote node's network through
> one of your NICs, THEN the traffic goes out the default gateway.  If you
> do have a route for the network, it goes out the NIC that has that
> route.
>
> As an example, assume a machine with two NICs.  eth0 has an IP of
> 192.168.0.2.  eth1 has an IP of 10.0.0.2.  The default gateway is
> 192.168.0.1 (obviously on eth1).
>
> Now, let's say you try to ping 10.24.1.1.  The traffic will go out eth0,
> since the default gateway (actually, the default route) is on eth0.
> However, you really want any traffic for 10.0.0.0/8 to go out on eth1.
> You set up a static route:
>
> 	route add -net 10.0.0.0 netmask 255.0.0.0 dev eth1
>
> Now, any traffic for the 10.0.0.0/8 network will go out eth1.  You
> can repeat that for as many networks (or hosts, if the netmask is /32)
> as you wish on each NIC (well, up to some practical limit).

Okay Rick, You're being nice. In the 'old days' when Kalum (Grendel) was
around (anyone find him?) you would have responded, "Uh Karl, you've been
smoking something" to which I would have to reply, "I've never started" and
"what do you suggest?" and you'd say something like "I've got some
great...." and then catch yourself not wanting to give out too much info...

Ahhhh, the 'good' old days.

Yes Rick, you're going soft. You're right on, but soft.

8^}

Karl

....and sorry to the rest of the list for wasting bandwidth. At least I
bottom-posted.

>
> ----------------------------------------------------------------------
> - Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
> - VitalStream, Inc.                       http://www.vitalstream.com -
> -                                                                    -
> -         If this is the first day of the rest of my life...         -
> -                        I'm in BIG trouble!                         -
> ----------------------------------------------------------------------
>
> _______________________________________________
> Redhat-install-list mailing list
> Redhat-install-list at redhat.com
> https://www.redhat.com/mailman/listinfo/redhat-install-list
> To Unsubscribe Go To ABOVE URL or send a message to:
> redhat-install-list-request at redhat.com
> Subject: unsubscribe
>


-- 
karl
     _/  _/      _/      _/_/_/       ____________   __o
    _/ _/       _/      _/    _/     ____________  _-\<._
   _/_/        _/      _/_/_/                     (_)/ (_)
  _/ _/       _/      _/           ......................
 _/   _/ arl _/_/_/  _/ earson    KarlP at ourldsfamily.com
---
Senior Consulting Sys/DB Analyst
http://consulting.ourldsfamily.com
---
 My Thoughts on Terrorism In America right after 9/11/2001:
 http://www.ourldsfamily.com/wtc.shtml
---
 A right is not what someone gives you; it's what no one can take from you.
 -Ramsey Clark
---

More information about the Redhat-install-list mailing list