Alcatel Carrier Internetworking Solutions Switch/Router 사용자 설명서

Page 27-25

As another example, to display a list of all global RIP Input filters, you would enter:

A screen similar to the following displays:

Whenever you use multiple “allow” filters you must first define a filter to block all RIPs or 
SAPs. Then, all of the seceding “allow” filters of the same type must be at least as specific in 
all areas in order for the filters to work. Note that filtering precedence is related only to 
“allow” filters. Multiple “block” filters can be defined with varying specificity in each of the 
areas of the filter. The filtering done by the configurable parameters (Net/Mask, Node/Mask, 
Service/Mode) in the “allow” filter must be at least as specific as the filtering defined in the 
“block” filter.

As an example, consider a switch that knows of multiple Type 4 SAPs on various networks, 
including a network with an address of “40.” The switch also knows of various types of SAPs 
on Network 40. For this example, you want to block all SAPs coming from Network 40, but 
you want to allow all Type 4 SAPs, including the ones that come from Network 40. 

To meet these objectives, you must configure the filters like this:

The filters shown below will not work for our example because in Filter 2 the type of service 
is less specific than the type defined in Filter 1. All Type 4 SAPs will be blocked by the filter.

The following filters will also not work because in Filter 2 the network and netmask are less 
specific than the network and netmask defined in Filter 1. All SAPs from Network 40 will be 
blocked by the filter.