Cisco Systems 3750E manual 34-23, Switchconfig# access-list 6 permit 172.20.128.64

Chapter 34 Configuring Network Security with ACLs

Configuring IPv4 ACLs

Use router ACLs to do this in one of two ways:

•Create a standard ACL, and filter traffic coming to the server from Port 1.

•Create an extended ACL, and filter traffic coming from the server into Port 1.

Figure 34-3 Using Router ACLs to Control Traffic

Server A	Server B
Benefits	Payroll

Port 2 Port 1

Human Resources 172.20.128.0-31

Accounting 172.20.128.64-95

101354

This example uses a standard ACL to filter traffic coming into Server B from a port, permitting traffic only from Accounting’s source addresses 172.20.128.64 to 172.20.128.95. The ACL is applied to traffic coming out of routed Port 1 from the specified source address.

Switch(config)# access-list 6 permit 172.20.128.64 0.0.0.31

Switch(config)# end

Switch# show access-lists

Standard IP access list 6

10 permit 172.20.128.64, wildcard bits 0.0.0.31

Switch(config)# interface gigabitethernet1/0/1

Switch(config-if)#ip access-group 6 out

This example uses an extended ACL to filter traffic coming from Server B into a port, permitting traffic from any source address (in this case Server B) to only the Accounting destination addresses 172.20.128.64 to 172.20.128.95. The ACL is applied to traffic going into routed Port 1, permitting it to go only to the specified destination addresses. Note that with extended ACLs, you must enter the protocol (IP) before the source and destination information.

Switch(config)# access-list 106 permit ip any 172.20.128.64 0.0.0.31

Switch(config)# end

Switch# show access-lists

Extended IP access list 106

10 permit ip any 172.20.128.64 0.0.0.31

Switch(config)# interface gigabitethernet1/0/1

Switch(config-if)#ip access-group 106 in

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		34-23