Redundant Cisco 4948E network design
Posted on 2013-05-10
I have two racks in a dc, the first (old) rack has a Cisco 4948E switch with an 10gig uplink to the DC Cisco switch (managed by them, I don't remember the exact model but it's something new and takes about 4-8U).
All the servers in the first rack are connected to the Cisco 4948E gigabit ports. This switch is operating as Layer3 switch with vlans and vlan interfaces. Each customer has it's own vlan and the Cisco 4948E is his gateway. The uplink port sits inside Vlan1 which has /29 IP configured and a default route to the DC's Cisco.
The new rack installed with a new Cisco 4948E switch. Currently there are no servers (yet) connected to him and his uplink is to the same DC's Cisco. This switch also use 10gig port for the uplink connection.
I asked the DC to put both switches in the same Vlan (from their side) so the new Cisco 4949E has an IP from the same /29.
The desired goal is to achieve redundancy, I would like to interconnect those two racks, using another 10gig connection between the Cisco 4948E switches.
The purpose is to eliminate single point of failure of one of the uplinks so I will have a redundant network path in case one of the uplinks goes down, and also to have load balancing and/or an ability to use the same IPs on both switches so that I can connect 2 HA x F5 LTMS with a floating IP each of them to other Cisco 4948E switch.
Thus i would like to connect a server to 2 F5 LTMs and gain a redundant highly available solution.
Both switches IOS support IP routing and all features.
I am not sure how to do it and what is the correct design topology.
I thought to create a trunk between the switches but probably STP will kill one of them.
DC team are ready to perform any needed changes or configurations on their switch.
I also thought about etherchannel but in my case I have two physical switches which are not stack-able (as far as I know). I ready about VSS technology which is also, unfortunately, not supported at those switches.
So I am not sure what is the correct way to do what I want.
Perhaps Layer 3 redundancy.... or some game play with L2 and STP.
All links must be active, both switches and f5 ltms have to be active-active, the ltms have a floating IP.
I need help to understand what are the recommended designs, which are available. If I a doing a mistake then I am ready to change the topology and rebuild it the right way.
Thank you very much.