RE: High Availability. (Maybe OT)

[David Wolsefer]

Kevin,   What you want to do is use multiple NICs on each server, connecting one NIC to each switch. If you need a 5 9s type of design, then you need to use 4 NICs with one NIC connecting to 2 different blades on each switch. In addition, if you need redundancy at the application layer, then you need clustering software. This does indeed work with Solaris. You should also investigate using the Arrowpoint switches for local and global load balancing. They will also solve problems such as maintaining stateful connections with cookies and SSL.   Regards,   David Wolsefer CCIE#5858 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Kevin Welch Sent: Friday, October 13, 2000 1:08 AM To: [EMAIL PROTECTED] Subject: High Availability. (Maybe OT) I am trying to figure out how to impliment a redundant network design.  The problem I keep running into is the connection to the server.  I can provide Access redundancy through the use of two switches.  I can provide some level of server redundancy via the use of 2 NICs or 2 Servers.  The problem is how to provide application layer redundancy.  I have been able to prove the network itself is redundant, but connectivity to servers seems to be where I am having trouble with my studies.   From my understanding I cannot do etherchannel accross switches, and more over, I remember that etherchannel does not provide redundancy because if one link goes down the whole channel goes down.  Please correct me if this is wrong.    Example:   Realizing that the expectation that a server stay up all the time would still be a single point of failure.  In the event of a network failure on a switch, how do I provide network access to the Server.    Proposed is to connect the server via a second NIC or second port on a dual or quad NIC to a secondary access switch.    Problem, maintaing the same layer 3 address accross both switches in the advent that one link should fail, the server maintains reachability.   Giving that in this case I would be talking about a solaris system, I have thought about using simple scripts to watch for the interface to go down and reconfigure.  I am curious if anyone knows of any hardware/software solutions for doing this?   I am guessing that I am not the first person to ask for something like this.   -- Kevin