Intergraph WebScale User Manual page 14

WebScale™
If you are using a router to connect your cluster to its clients, be sure that the router has
its proxy ARP support enabled. (This allows the router to map the cluster's primary IP
address and other multi-homed addresses to the corresponding MAC address.) If your
router does not route to the cluster with proxy ARP support enabled, you also can create
a static ARP entry in the router. Cisco routers require a static ARP entry because they
do not support proxy ARP for multicast MAC addresses.
Single Network Interface Card Limitations
Note: The limitations described in this section apply only when multicast cluster MAC
address support is disabled. Starting with Version 2, a multicast cluster MAC address is
used by default for cluster operations. For backward compatibility with previous
versions, you can disable the use of multicast cluster MAC addressing in the WebScale
Setup dialog. In this case, please carefully read the limitations described below.
If you disable multicast support, you should install a dedicated network interface card
(NIC) to handle cluster traffic in order to achieve optimum performance and the full
range of networking functionality. Although it is possible to have a successful cluster
installation with only one NIC, there are two limitations to this approach:
Computers within the cluster will not be able to communicate among themselves
with any networking protocol, not just TCP/IP. This can be a special problem if
one or more of the clustered servers also act as primary and backup domain
controllers.
Networking traffic destined to individual servers within the cluster will generate
additional networking overhead for all machines in the cluster.
These limitations may not be important for many installations. If the computers within
the cluster are only accessed from outside the cluster (i.e., there are no intra-cluster
communications) and non-cluster communications are infrequent (for example short
nightly updates of the web server content to individual computers in the cluster), the use
of a single networking card should be sufficient. Also, it is always possible to test and
demo WebScale using a single network card prior to installing additional cards for
operational purposes.
The topic Setting Up the Windows NT Bindings contains special instructions for
setting up WebScale on computer with a single network interface card. When using a
single NIC, you later can add a second NIC later and follow the instructions in the
subsection for multiple network interface cards.
Quick Start Guide for Windows NT Experts
The following guide lets Windows NT experts quickly install and configure WebScale
for use. This guide assumes that you are familiar with installing network adapter cards
and driver software for Windows NT systems. For more detailed, step-by-step
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User's Guide