NASD :
Neighbor Aware Software Distribution (NASD) is a CA ITCM feature that enables an
agent to act as a Collaborating Agent for peer-enabled software Distribution. The
Collaborating Agents are configured to retain the software packages that the Neighbor
Aware Agents can download. Some agents in a subnet can be configured as
Collaborating Agents which connect to the scalability server and can download the
software package.
The NASD feature speeds up the software distribution as the collaborating agents can
serve other agents even if the limit of maximum simultaneous executions on Scalability
Server has been reached. If Scalability Server and agents are in different subnets, then
the network bandwidth is reduced as the number of direct downloads from Scalability
Server across subnets are reduced. As the Neighbor Aware Agents download the
software package from the Collaborating Agents in a local subnet network, the software
distribution is fast across the subnet
You can find more information in our product documentation chapter 6.
Regarding configuration policy.
From DSM explorer check the location as given below
ControlPanel->configuration->Defatult Computer Policy->DSM->Software Delivery->Scalability Server->Neighbour Aware Software Distrinution
and then paramter
Neighbour Aware Software Distrinution: Neighbour Aware Software Distribution: Enable agent collaboration for software deployment
Create a new policy and change settings, then apply it on problematic SS machine.