Eicon Networks 1530 - Manual (Page 53)

Security 53
Custom Security Features using IP Filters
By using IP filters you can create your own custom security solutions. For example, you can
limit local access to the Eicon 1530 for specific computers, accept incoming traffic only from
certain remote users or networks, or drop incoming or outgoing nuisance traffic.
• How Filtering Works ............................................................................................ 53
• Defining a New Filter ........................................................................................... 54
• ‘Edit Filters’ Page Options .................................................................................. 56
• Example: Dropping incoming traffic from a specific network ........................ 59
• Example: Allowing incoming traffic only from a specific network ................. 60
How Filtering Works
Each profile you define for a particular connection has its own set of filters (called the ‘filter
stack’). All data packets, incoming and outgoing, pass through the filter stack of the profile
being used for a particular connection. A filter stack can have up to 8 filters, allowing for
sophisticated results.
Data cascades through the filter stack as shown in the following diagram. If a packet matches
one of the filters in the stack, the filter action is performed.
Note: All incoming and outgoing data passes through the filter stack.
Once any filter is activated, data transfer will be affected.
Filter #2
Filter #1
Data that matches
Data that matches
Drop
Drop
Forward
Forward
Apply filter
conditions
Apply filter
conditions
Action
Action
Data that does
not match
Data that does
not match
Filter #8
Output from filter stack
Input to filter stack
Data that matches
Drop
Forward Apply filter
conditions
Action
Data that does
not match
No
Yes
Are any filters
active?
Bypass filter stack
Send all data into filter stack
Discard
Discard
Discard
Discard