second network adapter... local intranet between 4 cpus

second network adapter... local intranet between 4 cpus

Post by Brian Shapir » Sun, 28 Jan 2001 01:28:11



I think the only dumb questions are the ones not asked so.....

I hope this is clear enough.

Our AIX systems are equipped with 2nd ethernet adapters and I can
assign them
additional IP addresses. I want to tell each computer to access any
one of the
other 3 systems via the second adapter. Thus eliminating local only
traffic from
our regular net and thus improving performance for the regular network

users and creating a local intranet running at 100 Mbs for
communications
between only these four machines.

Define the cards is easy enough but can anyone give me pointers on
configuring routing/route tables for this. On our regular internet
connections
routed is not running as gateways are hard coded (vs dynamically, the
net
guys tweaked the router to eliminate support for dynamic route updates

via routed). Also, I suspect it is important to note that the second
set of IP
addresses is still in the same sub net.

Anyway, I will eventually get this in one of my AIX classes but I
would like
to get this up and working in the near future so any help would be
appreciated.

Thanks!

Brian Shapiro

--
Brian D. Shapiro,  Systems Support Specialist
Ohio University Computer Services
208B Computer Services Center
Athens, Ohio   45701
----------------------------------------------------------


 
 
 

second network adapter... local intranet between 4 cpus

Post by Simon Marches » Sun, 28 Jan 2001 02:07:57


This is not recommended to achieve what you want. I recommend choosing
one of the subnets reserved for private comms, as specified in the
following:

http://www.faqs.org/rfcs/rfc1918.html

The Internet Assigned Numbers Authority (IANA) has reserved the
following three blocks of the IP address space for private internets:

10.0.0.0        -   10.255.255.255  (10/8 prefix)
172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
192.168.0.0     -   192.168.255.255 (192.168/16 prefix)


> Also, I suspect it is important to note that the second
> set of IP addresses is still in the same sub net.


 
 
 

second network adapter... local intranet between 4 cpus

Post by Jose Pina Coelh » Sun, 28 Jan 2001 13:24:34



> I think the only dumb questions are the ones not asked so.....

Not quite.  There *are* dumb questions all arround, but it's Waaaaay
dumb not to ask!

Quote:> [...]Also, I suspect it is important to note that the second
> set of IP addresses is still in the same sub net.

Yes, one of the most important things, it can cause no end of
trouble and as a bonus, in a non-deterministic way.
Aparently you have enough sense to recognize that as relevant
and that is GOOD.

To make it short:  Simon Marchese has already sent you on the right
road (the private networks RFC).

Let's assume you have a common network 1.2.3.x (netmask 255.255.255.0)
and the machines are A, B, C & D.

A -> 1.2.3.1
B -> 1.2.3.2
C -> 1.2.3.3
D -> 1.2.3.4

Now, add a private network for the 100Mbps network: 10.4.5.x (netmask
255.255.255.0)
A -> 10.4.5.1
B -> 10.4.5.2
C -> 10.4.5.3
D -> 10.4.5.4

Now, this is enough to communicate between A,B,C&D at 100Mbps, providing
you select the machines by IP.

To make sure that it allways runs at 100Mbps between those 4 machines,
at each of them, add an extra set of routes like:
On machine A:
route add 1.2.3.2 10.4.5.2  # Mach B
route add 1.2.3.3 10.4.5.3  # Mach C
route add 1.2.3.4 10.4.5.4  # Mach D

(i.e.: for each IP on the 10Mbps net, add a route through the 100Mbps
net).
Repeat on each of the other 3 machines with the obvious changes.

The end of /etc/rc.net is the correct place to add these, since at this
stage you are not ready to muck with the ODM.

Welcome to AIX. :-)

--
Doing AIX support was the most monty-pythonesque
activity available at the time.

 
 
 

1. howto configure two ethernet adapters as two real separate computers ( on the same cpu )

Hi,

I recently added a second ethernet adapter on my linux server. I had
problems with modules but this is an old story now.
I am now trying to configure my both ethernet cards but I get another
problem.

In fact, when I download or upload files from another station on this
network, my linux server cannot consider these cards as two real different
hosts and my tcp/ip packets are coming from and are going through both cards
because these two cards are on the same network.

Here are my configuration.

eth0 = 192.168.123.4
eth1 = 192.168.123.3

Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt
Iface
192.168.123.0   0.0.0.0         255.255.255.0   U        40 0          0
eth0
192.168.123.0   0.0.0.0         255.255.255.0   U        40 0          0
eth1
127.0.0.0       0.0.0.0         255.0.0.0       U        40 0          0 lo
0.0.0.0         192.168.123.254 0.0.0.0         UG       40 0          0
eth1

So is that possible to configure these cards as two real different hosts ???

Thanks
vincent

2. Qdisc drops not being reported to user space

3. firewall computer, local area network, intranet

4. recording level indication?

5. Two network adapters on seperate networks problem

6. Using Nagios to monitor UPS traps and generate SMS Notifications.

7. two network cards, two(?) networks, one computer...

8. Cron Question

9. added second nic, need help configuring it for local network

10. Two network adapters

11. installing two network adapter cards

12. Two network adapters anyone ?

13. Two network adapters