Command Reference Guide

3Com Router 3000 Ethernet Family
Command Reference Guide
Chapter 6 IP Routing Policy Configuration
Commands
3Com Corporation
6-17
index-number: Identifies an item in the prefix address list. The item with smaller
index-number will be tested first.
permit: Specifies the match mode of the defined address prefix list items as permit
mode. In the permit mode, if the IP address to be filtered is in the defined range, it will
not be tested by the next node. Otherwise, it has to go on with the test.
deny: Specifies the match mode of the defined address prefix list items as deny mode.
In the deny mode, the IP address in the defined range cannot pass the filtering and is
refused to go on with the next test. Otherwise, it will have the next test.
network: IP address prefix range (IP address). If it is 0.0.0.0 0, all the IP addresses are
matched.
len: IP address prefix range (mask length). If it is 0.0.0.0 0, all the IP addresses are
matched.
greater-equal, less-equal: Specifies the address prefix range [greater-equal, less-equal]
to be matched after the address prefix network len has been matched. The meaning of
greater-equal is "greater than or equal to" , and the meaning of less-equal is "less
than or equal to". The range is len <= greater-equal <= less-equal <= 32. When only
greater-equal is used, it indicates the prefix range [greater-equal, 32]. When only
less-equal is used, it indicates the prefix range [len, less-equal].
Description
Use the ip ip-prefix command to configure an address prefix list or one of its items.
Use the undo ip ip-prefix command to delete an address prefix list or one of its items.
The address prefix list is used for IP address filtering. An address prefix list may contain
several items, and each item specifies one address prefix range. The inter-item
filtering relation is "OR", i.e. passing an item means passing the filtering of this address
prefix list. Not passing the filtering of all items means not passing the filtering of this
prefix address list.
The address prefix range may contain two parts, which are determined by len and
[greater-equal, less-equal] respectively. If the prefix ranges of these two parts are both
specified, the IP to be filtered must match the prefix ranges of these two parts.
If you specify network len as 0.0.0.0 0, it only matches the default route.
Specify network len as 0.0.0.0 0 less-equal 32 to match all the routes.
Example
# Configure an address prefix list named p1. It permits the routes with the mask of 17 or
18 bits long and in network segment 10.0.192.0.8 to pass.
[3Com ] ip ip-prefix p1 permit 10.0.192.0 8 greater-equal 17 less-equal 18