Very Computer

by **qazmlp1..** » Sun, 14 May 2006 18:41:14

Sometime back, I had asked this question. But, the answer is still
unclear for me.
Can we use 'IP alias' for Single node(i.e.single server, no cluster
configuration) machines?

Here goes the requirement:
There is a single node server running and it is required to provide
'failover' in case of IP interface failure. The idea is that the server
will have 2 IP interfaces and if one of them fails, the client should
be able to contact the server via the other IP interface transparently.

Is it possible to provide 'IP alias' configuration for this requirement
and publish that IP for connection from external clients?

by **News** » Sun, 14 May 2006 19:50:13

> Sometime back, I had asked this question. But, the answer is still
> unclear for me.
> Can we use 'IP alias' for Single node(i.e.single server, no cluster
> configuration) machines?

> Here goes the requirement:
> There is a single node server running and it is required to provide
> 'failover' in case of IP interface failure. The idea is that the server
> will have 2 IP interfaces and if one of them fails, the client should
> be able to contact the server via the other IP interface transparently.

> Is it possible to provide 'IP alias' configuration for this requirement
> and publish that IP for connection from external clients?

Yes. See the docs for IPMP.

This page gives a worked example.
http://www.eng.auburn.edu/~doug/howtos/multipathing.html

by **qazmlp1..** » Sun, 14 May 2006 22:53:40

> > Is it possible to provide 'IP alias' configuration for this requirement
> > and publish that IP for connection from external clients?

> Yes. See the docs for IPMP.

> This page gives a worked example.
> http://www.eng.auburn.edu/~doug/howtos/multipathing.html

Thanks for the info!
I understand that IPMP can be used for 'failover' requirement on single
node machines. But, I am curious to know whether 'IP alias' can also be
used for this purpose. If not/yes, why?

My understanding till now is that,
- 'IP alias'/'Virtual IP' can be used for failover purpose when the
failover should be provided for more than 1 node, and
- IPMP can be used for failover, both within a single node and also
for more than 1 node configuration.
Could you clarify this, if possible in details?

Thanks!

by **News** » Mon, 15 May 2006 01:52:36

>> > Is it possible to provide 'IP alias' configuration for this requirement
>> > and publish that IP for connection from external clients?

>> Yes. See the docs for IPMP.

>> This page gives a worked example.
>> http://www.eng.auburn.edu/~doug/howtos/multipathing.html
> Thanks for the info!
> I understand that IPMP can be used for 'failover' requirement on single
> node machines. But, I am curious to know whether 'IP alias' can also be
> used for this purpose. If not/yes, why?

> My understanding till now is that,
> - 'IP alias'/'Virtual IP' can be used for failover purpose when the
> failover should be provided for more than 1 node, and
> - IPMP can be used for failover, both within a single node and also
> for more than 1 node configuration.
> Could you clarify this, if possible in details?

If you want an IP to move between two servers you need some extra software.
Something like freeha
http://www.bolthole.com/freeha/
or ucarp
http://www.ucarp.org/project/ucarp
or even Sun Cluster - but that is a full blown failover/ha package.

by **Barry Margoli** » Mon, 15 May 2006 09:17:54

> > > Is it possible to provide 'IP alias' configuration for this requirement
> > > and publish that IP for connection from external clients?

> > Yes. See the docs for IPMP.

> > This page gives a worked example.
> > http://www.eng.auburn.edu/~doug/howtos/multipathing.html
> Thanks for the info!
> I understand that IPMP can be used for 'failover' requirement on single
> node machines. But, I am curious to know whether 'IP alias' can also be
> used for this purpose. If not/yes, why?

IP alias is for assigning multiple addresses to one NIC. But your
question is about a machine with two NICs.

--

Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

by **Scott Howar** » Mon, 15 May 2006 09:49:49

> Is it possible to provide 'IP alias' configuration for this requirement
> and publish that IP for connection from external clients?

Yes.

ifconfig ce0 addif 10.1.1.2 netmask + broadcast + up

Scott

Very Computer

'IP alias' for single node machines?

'IP alias' for single node machines?

'IP alias' for single node machines?

'IP alias' for single node machines?

'IP alias' for single node machines?

'IP alias' for single node machines?

'IP alias' for single node machines?