Cisco Systems 4500 IP Unnumbered Configuration Guidelines and Restrictions

14-3
Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 14 Configuring IP Unnumbered Interface IP Unnumbered Configuration Guidelines and Restrictions
Figure 14-2 Format of the Agent Remote ID Suboption
Table 14-1 describes the agent remote ID suboption fields displayed in Figure 14-2.
IP Unnumbered Interface with Connected Host Polling
Note This feature option is applicable to LAN and VLAN interfaces only.
In some cases, the host IP address is assigned statically. The IP Unnumbered Interfaces feature can learn
the static host IP address dynamically.
IP Unnumbered Configuration Guidelines and Restrictions
When using (or configuring) IP Unnumbered Interface, consider these guidelines and restrictions:
• For IP Unnumbered Interfaces, the following features are not supported:
– Dynamic routing protocols
– HSRP/VRRP
– Static ARP
– Unnumbered Interface and Numbered Interface in different VRFs
Type
(byte 1) Length (byte 2) Interface (byte 9) Reserved (byte 10)
Reserved
(bytes 3-4) VLAN ID (bytes 11-12)
NAS IP address
(bytes 5-8)
103088
1 12 bytes
Table 14-1 Agent Remote ID Suboption Field Descriptions
Field Description
Type Format type. The value 2 specifies the format for use with this feature.
(1 byte)
Length Length of the Agent Remote ID suboption, not including the type and
length fields. (1 byte)
Reserved Reserved. (2 bytes)
NAS IP Address IP address of the interface specified by the ip unnumbered command.
(4 bytes)
Interface Physical interface. This field has the following format:
slot (4 bits) | module (1 bit) | port (3 bits).
For example, if the interface name is interface ethernet 2/1/1, the slot
is 2, the module is 1, and the port is 1. (1 byte)
Reserved Reserved. (1 byte)
VLAN ID VLAN identifier for the Ethernet interface. (2 bytes)