Cisco Systems OL-7822-06 Configuring ACLs, Entry Formats, Initial IP address, Wildcard bits, 4-13

Models: OL-7822-06

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Configuring ACLs

Chapter 4 Connect the Management Interfaces and Perform Initial System Configuration

Perform the Initial System Configuration

Configuring ACLs

The SCE 1000 can be configured with Access Control Lists (ACLs), which are used to permit or deny incoming connections on any of the management interfaces.

Note ACL #0 is a pre-defined list that permits access to all IP addresses.

Configuration of access control lists is done in two stages:

1.Create the access control lists.

You may create 99 ACLs with a maximum of 20 entries per list. Each entry consists of an IP address, and an indication of whether access is permitted or denied to this IP address.

2.Assign the ACLs to the appropriate management interface. (See )

The dialog permits you to skip the creation/editing of the ACLs and go directly to assigning ACLs to the management interfaces.

Entry Formats

Each ACL may permit/deny access to any IP address, one or more ranges of IP addresses, or one or more individual IP address. Three entry formats are available to support these options:

Any IP address — Type the word “any”. Any IP address will be permitted or denied access.

Range of IP addresses — Type the beginning IP address in the desired range, then enter the wildcard bits that define the range.

This wildcard functions like a reverse mask, in that all “1” bits in the wildcard indicate the corresponding bit in the IP address should be ignored. All other bits must match the corresponding bit in the specified IP address. Refer to the table below for examples.

Each range of IP addresses can be configured to be permitted or denied access.

Individual IP address— Type the desired IP address, then enter the wildcard bits 0.0.0.0.

Each individual IP address can be configured to be permitted or denied access.

Table 4-2

IP address/Wildcard bit examples

 

 

 

 

Initial IP address

Wildcard bits

Range

 

 

 

 

10.1.1.0

 

0.0.0.255

10.1.1.0–10.1.1.255

 

 

 

 

10.1.1.0

 

0.0.0.63

10.1.1.0–10.1.1.63

 

 

 

 

10.1.1.0

 

0.0.0.0

10.1.1.0 (individual entry)

 

 

 

 

Order of Entries

The order of the entries in the list is important. The entries in the list are tested sequentially, and the action is determined by the first entry that matches the connecting IP address. Therefore, when the entry “any” appears in an Access Control List, all succeeding entries are irrelevant.

Consider two hypothetical ACLs containing the same entries in a different order.

The following list would permit access to all IP addresses, including 10.1.1.0:

permit any

deny 10.1.1.0

Note that the above list could not actually be created using the setup utility, since after the “any” entry, no other entries could be added to the list.

Cisco Service Control Engine 1000 2xGBE Quick Start Guide

 

OL-7822-06

4-13

 

 

 

Page 33
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Cisco Systems OL-7822-06 Configuring ACLs, Entry Formats, Initial IP address, Wildcard bits, Range, Order of Entries, 4-13