50   ESR Series Routers Operation Manual 
esr(config-zone-rule)# match destination-address LAN 
esr(config-zone-rule)# match source-address LAN_GATEWAY 
esr(config-zone-rule)# enable 
esr(config-zone-rule)# exit 
esr(config-zone-pair)# exit 
esr(config)# exit 
Configuration changes will take effect when the following commands are executed: 
esr# commit 
Configuration has been successfully committed 
esr# confirm 
Configuration has been successfully confirmed 
esr# 
To view port membership in zones, use the following command:  
esr# show security zone 
To view zone pairs and their configuration, use the following commands: 
esr# show security zone-pair 
esr# show security zone-pair configuration 
To view active sessions, use the following commands: 
esr# show ip firewall sessions 
7.9  Access list (ACL) configuration 
Access  Control  List  or  ACL  is  a  list  that  contains  rules  defining  traffic  transmission  through  the 
interface. 
Objective: Allow traffic transmission from 192.168.20.0/24 subnet only. 
 
Solution: 
Configure access control list for filtering by a subnet: 
 
esr# configure 
esr(config)# ip access-list extended white 
esr(config-acl)# rule 1 
esr(config-acl-rule)# action permit 
esr(config-acl-rule)# match protocol any 
esr(config-acl-rule)# match source-address 192.168.20.0 255.255.255.0 
esr(config-acl-rule)# match destination-address any 
esr(config-acl-rule)# enable 
esr(config-acl-rule)# exit 
esr(config-acl)# exit 
 
Apply access list to Gi1/0/19 interface for inbound traffic: 
esr(config)# interface gigabitethernet 1/0/19 
esr(config-if-gi)# service-acl input white 
 
Configuration changes will take effect when the following commands are executed: