]> IP address, i.e. IPv4 address (or IPv4 subnet mask) or IPv6 address. All IPv4 addresses and subnet masks MUST be represented as strings in IPv4 dotted-decimal notation. Here are some examples of valid IPv4 address textual representations: * 216.52.29.100 * 192.168.1.254 All IPv6 addresses MUST be represented using any of the 3 standard textual representations defined in {{bibref|RFC4291}} Sections 2.2.1, 2.2.2 and 2.2.3. Both lower-case and upper-case letters can be used, but use of lower-case letters is RECOMMENDED. Here are some examples of valid IPv6 address textual representations: * 1080:0:0:800:ba98:3210:11aa:12dd * 1080::800:ba98:3210:11aa:12dd * 0:0:0:0:0:0:13.1.68.3 IPv6 addresses MUST NOT include zone identifiers. Zone identifiers are discussed in {{bibref|RFC4007|Section 6}}. Unspecified or inapplicable addresses (or IPv4 subnet masks) MUST be represented as empty strings unless otherwise specified by the parameter definition. IPv4 address (or subnet mask). Can be any IPv4 address that is permitted by the ''IPAddress'' data type. IPv6 address. Can be any IPv6 address that is permitted by the ''IPAddress'' data type. IPv4 or IPv6 routing prefix in Classless Inter-Domain Routing (CIDR) notation {{bibref|RFC4632}}. This is specified as an IP address followed by an appended "/n" suffix, where ''n'' (the prefix size) is an integer in the range 0-32 (for IPv4) or 0-128 (for IPv6) that indicates the number of (leftmost) '1' bits of the routing prefix. IPv4 example: 192.168.1.0/24 IPv6 example: 2001:edff:fe6a:f76::/64 Unspecified or inapplicable IP prefixes MUST be represented as empty strings unless otherwise specified by the parameter definition. IPv4 address prefix. Can be any IPv4 prefix that is permitted by the ''IPPrefix'' data type. IPv6 address prefix. Can be any IPv6 prefix that is permitted by the ''IPPrefix'' data type. All MAC addresses are represented as strings of 12 hexadecimal digits (digits 0-9, letters A-F or a-f) displayed as six pairs of digits separated by colons. Unspecified or inapplicable MAC addresses MUST be represented as empty strings unless otherwise specified by the parameter definition. A 32-bit statistics parameter, e.g. a byte counter. This data type SHOULD NOT be used for statistics parameters whose values might become greater than the maximum value that can be represented as an ''unsignedInt''. ''StatsCounter64'' SHOULD be used for such parameters. The actual value of the statistic might be greater than the maximum value that can be represented as an ''unsignedInt''. Such values SHOULD wrap around through zero. The term ''packet'' is to be interpreted as the transmission unit appropriate to the protocol layer in question, e.g. an IP packet or an Ethernet frame. A 64-bit statistics parameter, e.g. a byte counter. This data type SHOULD be used for all statistics parameters whose values might become greater than the maximum value that can be represented as an ''unsignedInt''. The term ''packet'' is to be interpreted as the transmission unit appropriate to the protocol layer in question, e.g. an IP packet or an Ethernet frame. A non-volatile handle used to reference this instance. Alias provides a mechanism for an ACS to label this instance for future reference. If the CPE supports the Alias-based Addressing feature as defined in {{bibref|TR-069a4|3.6.1}} and described in {{bibref|TR-069a4|Appendix II}}, the following mandatory constraints MUST be enforced: *Its value MUST NOT be empty. *Its value MUST start with a letter. *If its instance object is created by the CPE, the initial value MUST start with a "cpe-" prefix. *The CPE MUST NOT change the parameter value.