Intergraph WebScale User Manual page 70

WebScale™
physical NIC if you are using only one NIC. If the problem persists, the network
problem is not related to WebScale.
3. If you are using a switch to interconnect the cluster hosts, you must use
WebScale's multicast support. Otherwise, the switch is likely to behave
erratically when the same unicast network is used on multiple switch ports.
Check that you have selected multicast support in the WebScale Setup dialog. If
you do not want to use multicast support, you can interconnect the cluster hosts
with a hub or coaxial cable instead of a switch.
Problem: Cluster unreachable from outside network
Description: When I ping the cluster's primary IP address from an outside network, I
get no response.
Probable cause(s) and resolution:
1. The cluster hosts may be unreachable from an outside network. Verify that you
can ping the dedicated IP addresses for the cluster hosts from a system outside
the router. If this test fails and you are using multiple
unreachable due to a problem unrelated to WebScale. If you are using a single
NIC for both the dedicated and cluster IP addresses, go on to the next step.
2. If you are using multicast support, you may find that your router has difficulty
resolving the primary IP address into a multicast network address using the ARP
protocol. To check this, verify that you can ping the cluster from a client on the
cluster's subnet and that you can ping the cluster hosts' dedicated IP addresses
from a system outside the router. If these tests work properly, the router is
probably at fault. Cisco routers are known to exhibit this problem. You should be
able to add a static ARP entry to the router to circumvent the problem. You can
also turn off WebScale's multicast support and use a unicast network address
without a switch.
3. When using WebScale in either multicast or unicast mode, routers need to be able
to accept proxy ARP responses (IP to network address mappings that are received
with a different network source address in the Ethernet frame). Make sure that
your router has proxy ARP support turned on. You can also set a static ARP entry
if you wish to keep proxy ARP support disabled in the router.
4. If you are using unicast support, the cluster NIC could not change its network
address. This problem only occurs when using a unicast network address (instead
of a multicast address). You should either switch to a different cluster adapter
card or use WebScale's multicast support.
Problem: Outside system (possibly on same subnet) unreachable from a cluster host
Description: When I ping a system outside the cluster from a cluster host, I get no
response.
Probable cause(s) and resolution:
1. The outside system may be unreachable from a cluster host. If you are using
multiple NIC's, the system is unreachable due to a problem unrelated to
NIC's
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User's Guide
, the cluster is