Ohhhhh, I get it! I had to read your description a couple
of times before I understood what you meant (at least I
*THINK* I do! :). My best guess is that your
network diagram looks like:
____________ _____________
| AIX ADSM | Network A | NT Client |
| Server | eth2 |
|
|___________== Gb/s Ethernet ====____________|
en0 || ||
(eth0, eth1)
2x100Mb/s // \\
Ethernet* Network B
* Only one of eth0 or eth1 interface is active at a time
NB: en0 is our AIX Gb Ethernet interface
eth0, eth1 are our NT 100Mb Ethernet interfaces
on the same card (?? sounds bizarre)
eth2 is our NT Gb Ethernet interface
Fig 1: Network diagram
Given this diagram, Network A connects the AIX box and NT box.
If Network A is is a dedicated backup network ONLY for the NT box,
then making sure that Network A is, for instance, a non-routable IP
network like 192.168.10.0 will solve your problems. Your AIX box's
en0 interface will be something like 192.168.10.1 and the NT box's
eth2 interface will be something like 192.168.10.2.
However, I suspect that the reason you want IP aliasing is because
your Network A contains the AIX box, the NT box PLUS a bunch
of other boxes. In this case, Network A == Network B.
If this is the case, you need (as you've stated) a way to specify that
backup traffic goes through the eth2 interface, rather than through the
eth0 or eth1 interfaces -- ie a "virtual Ethernet network" between the
NT and AIX box, which is done using an IP alias on the AIX. (Whew! :)
Let's assume that your "real" network uses a Class A address space
of 10.10.10.0 (with a Class C subnet mask :). As an example, your eth0
and eth1 interfaces provide the IP address of 10.10.10.6 (and same MAC
address, hopefully -- this reduces arp cache timeout problems). The
en0 interface on the AIX box has an IP of something like 10.10.10.42 .
What we need to accomplish is to have two separate networks:
Network A and Network B. Network B is in place and working,
and the AIX box has a working IP address here. After adding the
IP alias (re-using the 192.168 addresses) on the AIX box of
192.168.10.1, and making sure that the NT has an IP of 192.168.10.2,
theoretically we should be done.
I've just done this between an AIX 4.3.2 box and a Solaris 2.5.1 box.
I didn't need to do anything more complicated on the AIX side than
smitty tcpip
-> Further Configuration
-> Network Interfaces
-> Network Interface Selection
-> Configure Aliases
-> Add an IPV4 Network Alias
IP: 192.168.10.1
Netmask: 255.255.255.0
NB: If you don't do it through smitty, undo what you've done, and
use smitty. It's more macho to use the command line, but it's
MUCH more error-prone than using smitty. If you don't mind
playing the game of "What do I need to do in the ODM?", you
can have hours of entertainment the whole network can enjoy too!
As far as both the AIX and NT boxes knowing each other's MAC
address, that's the way that Ethernet works. IP addresses get translated
to MAC addresses, and the stream of data goes across the network.
The analogy I like to use is that an IP address is like a street address (ie
1241 Kilborn Place, Ottawa, Canada) and a MAC address is
like the city planner's lot and section numbers (I'm completely making
this part up, but ie lot 27, section 4 ). You and I use the street addresses
in order to figure out how to get from one area of the city to another (or
even WHICH city! :) whereas the city planners need a more exact
and predictable reference in order to determine where to put fire hydrants, etc.
The name would be the building name: ie the Waterford Apartments.
(Ok, ok! It's not a great analogy, but hopefully you get what I mean. :)
Now, I have no idea if I'm telling you things you already know, so I apologize
in advance you're VERY familiar with the OSI model / TCP/IP stack stuff, and
you were mentioning the MAC address stuff as something that annoyed you.
("If you can figure out the MAC, why can't you respond to a ping, you silly
arp cache/router!" :)
Hope that the above helps...
kells
"Any coincidence of opinions, real or imagined, between myself and
Mainland Information Systems Ltd is exactly that."
Reinhold Wagner wrote:
> Roger,
>
> my ADSM server has just a single gigabit ethernet card while
> my NT client has two ethernet cards which are connected to
> the same physical networks (yes, via a ethernet switch).
>
> The 100 mbit card has two ports and provides fail over (both
> ports are connected to different switches). So communication
> with the users must be done with this NIC.
>
> To achieve a _super_ backup performance we added an additional
> (gigabit) network card. NT supports different IP networks on
> every card - but my ADSM server (AIX) has just one network
> card :-(
>
> So i added an IP alias on AIX in order to perform the
> backup via both gigabit's. But AIX does not respond to
> a ping on it's second network address. Interesting is,
> that both ping partners know each other's MAC address !?
>
> Any idea?
>
> Reinhold Wagner, Zeuna Staerker GmbH & Co. KG
>
> Roger Hohmann <Roger_Hohmann AT WESTLB DOT DE> on 19.08.99 12:32:02
>
> Bitte antworten an "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
>
> An: ADSM-L AT VM.MARIST DOT EDU
> Kopie: (Blindkopie: Reinhold Wagner/A/DE/ZEUNA)
> Thema: Re: IP-Alias on ADSM/AIX server
>
> Reinhold,
>
> why are You doing this? Why not only one ip address for each nw card? To
> select the client nw card You can use tcpclientaddress?? Maybe Your NT
> server or a router/bridge becomes confused about a single mac address
> with 2 ip adresses?
>
> AFAQ, it doesn't matter if 2 logical networks are on the same physical
> net or not. You need some kind of router between both nets. I wonder how
> to drive Gigabit and 100tx on the same 'physical net'. I would expect
> some kind of switching hub or router between them.
>
> Regards
>
> Roger
>
> Reinhold Wagner schrieb:
> >
> > Folks,
> >
> > we have a difficult problem which we can't solve. I know that it's not an
> > ADSM
> > problem but i spent severall days to get it work but had no success.
> >
> > Our equipment:
> >
> > ADSM server on RS/6000 AIX vers. 4, ADSM vers. 3, 1 gigabit ethernet card
> > NT client, 1 100 mbit ethernet card, 1 gigabit card
> >
> > The gigabit card of the nt server should be used only for backup.
> >
> > The NT box has a different ip network on every network interface (172.17.x.x
> on
> > 100 mbit,
> > 172.20.x.x on the gigabit card). But both interfaces are connected to the
> > same
> > physical
> > network.
> >
> > I defined an IP alias on my ADSM server with the network 172.20.x.x
> >
> > The NT client answers on pings on both networks. The AIX server does not
> answer
> > pings on 172.20.x.x.
> >
> > This are the static routes:
> >
> > 172.17/16 172.17.1.118 U 29 615422426 en0 - -
> > 172.18/16 172.17.1.12 UG 0 0 en0 - -
> > 172.20/16 172.20.1.118 UG 0 951 en0 - -
> >
> > ifconfig -a:
> >
> > en0:
> flags=e080863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST,GROUPRT,64B
> > IT>
> > inet 172.17.1.118 netmask 0xffff0000 broadcast 172.17.255.255
> > inet 172.20.1.118 netmask 0xffff0000 broadcast 172.20.255.255
> >
> > Funny: If i ping from AIX to NT and vice versa, both machines know the mac
> > address
> > of the other box (arp -a) but i don't get an answer at all!
> >
> > Any ideas?
> >
> > TIA
> >
> > Reinhold Wagner, Zeuna Staerker GmbH & Co. KG
>
> --
> Roger Hohmann
> Westdeutsche Landesbank Girozentrale
> Division: 009 Services
> Abteilung: 001-80622
> Herzogstra_e 15
> D - 40217 D|sseldorf
> Tel.: +49211 826 8155
> Fax : +49211 826 5393
> mailto:roger_hohmann AT westlb DOT de
|
