SROS Command Line Interface Reference Guide

ATM Sub-Interface Config Command Set

 

 

Usage Examples

The following example associates the access policy UnTrusted (to allow inbound traffic to the Web server) to the ATM sub-interface labeled 1.1:

Enable the Secure Router OS security features:

(config)#ip firewall

Create the access list (this is the packet selector):

(config)#ip access-list extended InWeb (config-ext-nacl)#permit tcp any host 63.12.5.253 eq 80

Create the access policy that contains the access list InWeb:

(config)#ip policy-class UnTrusted (config-policy-class)#permit list InWeb

Associate the access list with the ATM 1.1 interface:

(config)#interface atm 1.1

(config-atm1.1)#access-policy UnTrusted

Technology Review

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 deny 192.168.0.0 0.0.0.255 will deny 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 permit, deny, 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:

5991-2114

© Copyright 2005 Hewlett-Packard Development Company, L.P.

650

Page 650
Image 650
HP 7000 dl Router manual Config#ip firewall, Config#interface atm Config-atm1.1#access-policy UnTrusted