Cisco 3845 Software Guide - Page 466

Configuring IPv4 ACLs Chapter 26 Configuring Network Security with ACLs Including Comments in ACLs You can use the remark keyword to include comments (remarks) about entries in any IP standard or extended ACL. The remarks make the ACL easier for you to understand and scan. Each remark line is limited to 100 characters. The remark can go before or after a permit or deny statement. You should be consistent about where you put the remark so that it is clear which remark describes which permit or deny statement. For example, it would be confusing to have some remarks before the associated permit or deny statements and some remarks after the associated statements. To include a comment for IP numbered standard or extended ACLs, use the access-list access-list number remark remark global configuration command. To remove the remark, use the no form of this command. In this example, the workstation that belongs to Jones is allowed access, and the workstation that belongs to Smith is not allowed access: Switch(config)# access-list 1 remark Permit only Jones workstation through Switch(config)# access-list 1 permit 171.69.2.88 Switch(config)# access-list 1 remark Do not allow Smith through Switch(config)# access-list 1 deny 171.69.3.13 For an entry in a named IP ACL, use the remark access-list configuration command. To remove the remark, use the no form of this command. In this example, the Jones subnet is not allowed to use outbound Telnet: Switch(config)# ip access-list extended telnetting Switch(config-ext-nacl)# remark Do not allow Jones subnet to telnet out Switch(config-ext-nacl)# deny tcp host 171.69.2.88 any eq telnet Applying an IPv4 ACL to a Terminal Line You can use numbered ACLs to control access to one or more terminal lines. You cannot apply named ACLs to lines. You must set identical restrictions on all the virtual terminal lines because a user can attempt to connect to any of them. For procedures for applying ACLs to interfaces, see the "Applying an IPv4 ACL to an Interface" section on page 26-19. For applying ACLs to VLANs, see the "Configuring VLAN Maps" section on page 26-29. Beginning in privileged EXEC mode, follow these steps to restrict incoming and outgoing connections between a virtual terminal line and the addresses in an ACL: Step 1 Step 2 Command configure terminal line [console | vty] line-number Step 3 access-class access-list-number {in | out} Purpose Enter global configuration mode. Identify a specific line to configure, and enter in-line configuration mode. • console-Specify the console terminal line. The console port is DCE. • vty-Specify a virtual terminal for remote console access. The line-number is the first line number in a contiguous group that you want to configure when the line type is specified. The range is from 0 to 16. Restrict incoming and outgoing connections between a particular virtual terminal line (into a device) and the addresses in an access list. 26-18 Cisco ME 3800X and 3600X Switch Software Configuration Guide OL-23400-01