Creating an access control list
An access control list (ACL) defines clauses that identify which IP addresses to allow or deny access to a service. You assign an ACL to a service. Candidate addresses are evaluated against each clause sequentially. A candidate address is denied or granted access based on the first clause that matches. Therefore, the clause order is vital.
Before you begin
- The
rest-mgmtACL for use by the REST management interface. - The
sshACL for use by the SSH service. - The
web-mgmtACL for use by the web management service. - The
xml-mgmtACL for use by the XML management interface.
Each of these configurations, when enabled, provides full access from all IPv4 addresses. If the
Ethernet for the local address for these services supports IPv6 addresses, modify its ACL to include
an allow clause for specific or all IPv6 addresses.
About this task
The configuration of an ACL consists of a sequence of allow and deny clauses. Each clause identifies an IP address or range of addresses that allows or denies access. An ACL grants access to only addresses that allow clauses define. All other addresses are denied access.
10.10.100.0/28specifies the IPv4 address range from10.10.100.0through10.10.100.15.10.10.100.9/32specifies the single IPv4 address.0.0.0.0(without a prefix length) specifies all IPv4 addresses.::/0specifies all IPv4 and IPv6 addresses.
deny clause (192.168.14.224 - 192.168.14.255) is granted access before the
allow clause.allow 192.168.14.0/24
deny 192.168.14.0/27However, when you reverse the clause order, the ACL achieves its
intended purpose.deny 192.168.14.0/27
allow 192.168.14.0/24deny clauses effectively disables the service. To
complete the ACL, include an allow clause to ensure that addresses that are not
explicitly denied access are granted access. The following example denies access to two ranges of
addresses and allows access to all other IPv4 addresses.deny 10.10.10.0/24
deny 172.16.0.0/16
allow 0.0.0.0