Cluster Network Architecture and IP Aliasing
We have a 14 node cluster with a single NIC in each node up and
running. Because of the limited bandwidth, we are planning to install 2
additional NICS into each system and mesh the network using five 8-port
switches, with each switch residing in its own subnet. Then having each
node connected to 3 different switches. The problem for routing and host
lookup then becomes nightmarish.
If we set up each system with its own, unique routing table for each
possible route, and include alternate routes via other systems, the
resulting tables would require the destination IP to be changed depending on
the route taken. This leads to the question: Is it possible to alias one IP
address across three NICS on the same system, providing a single point of
reference across the cluster? Assuming that each node is connected to three
separate subnets (a separate subnet for each switch), and the aliased IP is
in a higher level subnet containing each of the separate subnets? For
example:
Using a 10.x.x.x address space,
Each switch (subnet) using 10.0.x.y where x is the switch, and y is each
connected node.
Each Virtual IP would reside in 10.x.0.0 where x would be the node number.
So each node would have 4 IP addresses, and all addressing going to the
virtual address. Routing using static routes would then become straight
forward for inter-node communication.
Node1
10.0.1.1 -------|\
10.0.2.3 -------| > 10.1.0.0
10.0.3.14 ------|/
Is this possible using IP Aliasing? And if so, could it affect system
stability? Or am I missing the point somewhere. Any help/feedback would be
greatly appreciated.
Shannon Bock
shannon.bock@kirtland.af.mil
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