Command Reference Guide

SROS Command Line Interface Reference Guide Global Configuration Mode Command Set
5991-2114 © Copyright 2005 Hewlett-Packard Development Company, L.P. 295
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Creating access policies and lists to regulate traffic through the routed network is a four-step process:
Step 1:
Enable the security features of the
Secure Router OS using the ip firewall command.
Step 2:
Create an access list to permit or deny specified traffic. Standard access lists provide pattern matching for
source IP addresses only. (Use extended access lists for more flexible pattern matching.) IP addresses
can be expressed in one of three ways:
1. Using the keyword any to match any IP address. For example, entering deny any will effectively shut
down the interface that uses the access list because all traffic will match the any keyword.
2. Using the host <A.B.C.D> to specify a single host address. For example, entering permit
196.173.22.253 will allow all traffic from the host with an IP address of 196.173.22.253.
3. Using the <A.B.C.D> <wildcard> format to match all IP addresses in a “range”. Wildcard masks work in
reverse logic from subnet mask. Specifying a one in the wildcard mask equates to a “don’t care”. For
example, entering discard 192.168.0.0 0.0.0.255 will discard all traffic from the 192.168.0.0/24 network.
Step 3:
Create an access policy that uses a configured access list.
Secure Router OS access policies are used to
allow, discard, or manipulate (using NAT) data for each physical interface. Each ACP consists of a selector
(access list) and an action (allow, discard, NAT). When packets are received on an interface, the
configured ACPs are applied to determine whether the data will be processed or discarded. Possible
actions performed by the access policy are as follows:
allow list <access list names>
discard list <access list names>
allow list <access list names> policy <access policy name>
discard list <access list names> policy <access policy name>
nat source list <access list names> address <IP address> overload
nat source list <access list names> interface <interface> overload
nat destination list <access list names> address <IP address>
Step 4:
Apply the created access policy to an interface. To assign an access policy to an interface, enter the
interface configuration mode for the desired interface and enter access policy <policy name>. The
following example assigns access policy MatchAll to the Ethernet 0/1 interface:
(config)#interface ethernet 0/1
(config-eth 0/1)#access-policy MatchAll