Black Box ET0010A User Manual

Advanced Uses for Networks in Policies

EncrypTight User Guide

161

ETPM accepts non-contiguous network masks, which allow you to create policies between particular 
addresses in your network. For example, a network of 10.0.0.1 with a mask of 255.0.0.255 allows all 
devices with an IP address of 10.x.x.1 to be managed by a particular policy. This feature is available only 
with ETEP PEPs. See 

If you are familiar with network addressing and network masks, you can use subnetting to make your 
policies more efficient. 

●

Use supernetting to reduce the number of SAs and keys on each PEP in large deployments.

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Use non-contiguous network masks to apply policies to a specific IP address scheme. 

Working with large networks, a considerable number of security associations (SAs) and keys can result 
on each PEP. One way to avoid this is to look for subnetworks within each network set that have 
contiguous addressing. You can combine these subnets to reduce the number of SAs and keys on each 
PEP. 

In 

, if you set up each of these networks as a separate network in ETPM, and the policy 

encrypts traffic between these two networks and five other networks, the PEP for this network set would 
contain 10 SAs and keys for each direction. 

As illustrated in 

, the two networks 192.168.2.0 with subnet mask 255.255.255.0 and 

192.168.3.0 with subnet mask 255.255.255.0 could be grouped into one network 192.168.2.0 with subnet 
mask 255.255.254.0.