How to configure 2 NICs to a Single IP in OS X

dstranathan · January 1, 2004 11:55AM

I have a beige G3 running OS X Server 10.2. The beige G3 has a 10 baseT on-board NIC (Apple OEM integrated on the mobo), as well as a PCI-based 10/100 Asante NIC.

Is there a way to bind BOTH NICs to the same IP, in such a way that if one NIC fails, the other NIC "kicks in" and provides redundnacy?

I have been able to give each NIC a seperate IP (i.e.; NIC #1 @10.0.1.10, and NIC #[email protected]), but that is not what I want. I want BOTH NICs to be bound to the same IP.

wmf · January 1, 2004 12:49PM

Quote:

Originally posted by dstranathan

Is there a way to bind BOTH NICs to the same IP, in such a way that if one NIC fails, the other NIC "kicks in" and provides redundnacy?

I don't think this is possible in OS X.

mr. me · January 1, 2004 4:47PM

Quote:

Originally posted by dstranathan

I have a beige G3 running OS X Server 10.2. The beige G3 has a 10 baseT on-board NIC (Apple OEM integrated on the mobo), as well as a PCI-based 10/100 Asante NIC.

Is there a way to bind BOTH NICs to the same IP, in such a way that if one NIC fails, the other NIC "kicks in" and provides redundnacy?

I have been able to give each NIC a seperate IP (i.e.; NIC #1 @10.0.1.10, and NIC #[email protected]), but that is not what I want. I want BOTH NICs to be bound to the same IP.

I think that you have to

barto · January 1, 2004 6:46PM

You could write a shell script to ping an address, and if that fails, change your ip address using ifconfig (eg ifconfig en0 10.0.0.3/16)

Maybe someone who knows how to write shell scripts can help you more

Barto

king chung huang · January 1, 2004 7:26PM

Xserves include software for this, although its for failing-over entire servers.

dstranathan · January 1, 2004 8:53PM

Quote:

Originally posted by Barto

You could write a shell script to ping an address, and if that fails, change your ip address using ifconfig (eg ifconfig en0 10.0.0.3/16)

Maybe someone who knows how to write shell scripts can help you more

Barto

What does the "/16" represent?

wmf · January 1, 2004 9:18PM

Quote:

Originally posted by dstranathan

What does the "/16" represent?

/16 means the subnet mask is 255.255.0.0 (the first 16 bits are 1).

dstranathan · January 2, 2004 9:05AM

Quote:

Originally posted by wmf

/16 means the subnet mask is 255.255.0.0 (the first 16 bits are 1).

Your examplw shas that the /16 refers to a class B subnet mask (255.255.0.0). Please give me another example of a fractional subnet mask value -but for this (class C) subnet mask: 255.255.255.0.

Would it be /24? /8? /32? /16?

dfiler · January 2, 2004 11:51AM

You could also look into the high-availability or heartbeat packages. A quick google indicates that people have got it working with os x. It is specifically designed to trigger scripts based upon network connectivity and will function with just a single node.

wmf · January 2, 2004 2:13PM

Quote:

Originally posted by dstranathan

Your examplw shas that the /16 refers to a class B subnet mask (255.255.0.0). Please give me another example of a fractional subnet mask value -but for this (class C) subnet mask: 255.255.255.0.

A subnet mask of 255.255.255.0 would be /24.

There's a subnet mask converter on this page: http://www.telusplanet.net/public/sparkman/netcalc.htm

moose · January 4, 2004 5:25PM

On my PowerBook, Airport and Ethernet are assigned to the same IP address, mask, etc.

When I plug my PowerBook into wired ethernet (rare), the only difference is that things are faster.

Nothing changes.

So.

What you want to do should be possible. Just set them both to the same IP address and let the OS take care of the rest. Have you actually been unable to set them both to the same IP address using System Preferences?

scott · January 4, 2004 6:43PM

Some networks are not very happy when two cards have the same IP.

nothing · January 4, 2004 8:43PM

http://www.hmug.org/man/8/failoverd.html

How to configure 2 NICs to a Single IP in OS X

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