User manual
Chapter 4 - Layer 3 Command Set - IP Networking OSPFv2 (Dynamic Routing Protocol Module)
Alvarion BreezeNET B130/B300 GigE 146 Operational User Manual
Prefixes lists (prefix-list)
Access lists consist of a set of operators. Each operator consists of a range of
IP-addresses and deny or permit command. The range of addresses is set as
<value> <mask for insignificant bits>. The object to be filtrated has its basic
parameter in the same format (IP-address, subnet etc). To make a decision
whether the object corresponds with a list, each operator from the list is
consequently applied to the basic parameter of the object until this parameter
satisfies the condition. When a right condition is met, the decision is made
according to the record in the command of the operator (deny or permit).
In OSPF router there are three types of access lists:
Standard. Is identified by numbers 1-99 or 1300-1999 and is used to analyze
one parameter of filtration object.
Extended. Is identified by numbers 100-199 or 2000-2699 and is used to
analyze two parameters of filtration object (for example, source address and
destination address).
Nominate. Identical to Standard but is identified by a name (not number).
Moreover, operators are configured in the format of <value>/<mask length>
In order to create or edit an access list in OSPF router the following commands are
used (in config mode):
This command creates an operator in a standard access list. Value and mask
define a range (criteria) for the operator. The mask defines those bits of the value
which form the range. For example, in order to specify the range of IP-address
from 192.168.12.0 to 192.168.255, one should specify the value of 192.168.12.0
and a mask of 0.0.0.255. For the value and mask of 0.0.0.0 255.255.255.255
there is a key word any. For example, the command:
OSPF(config)# access-list 1 permit 0.0.0.0 255.255.255.255
is equal to the command:
OSPF(config)# access-list 1 permit any
Table 4-9: Standard Access Lists
access-list (<1-99>|<1300-1999>) (deny|permit) A.B.C.D A.B.C.D
List identifier Command value Mask of bits
Range of values for the parameter