ATL Telecom R1-SW Ethernet Switch - Manual (Page 216)

R1-SW24L2B User’s Manual
10-6
Configuring Access Lists
Access Lists
Access lists filter network traffic by controlling whether routed packets are forwarded or
blocked at the system's interfaces. Your system examines each packet to determine whether to
forward or drop the packet, based on the criteria you specified within the access lists.
Access list criteria could be the source address of the traffic, the destination address of the traffic,
the upper layer protocol, or other information. Note that sophisticated users can sometimes
successfully evade or fool basic access lists because no authentication is required.
You can use standard access lists to control the Telnet or SNMP access methods to management
functions on the Corecess R1-SW24L2B.
In the above example, the access list allows access from the 172.20.128.64 host. Therefore the
host B connected to the Corecess R1-SW24L2B can access to the Server A or Server B and the
host A can’t access to the Servers.
R1-SW24L2B
Access list
x Source IP address : 172.20.128.64
x Permit/deny : Permit
x Flow : Out
Server A
Host A
IP: 172.20.128.10 Host B
IP: 172.20.128.64
Router
Internet or LAN
Server B