Brocade Communications Systems 6650 manual Sub-option 1 Circuit ID, Sub-option 2 Remote ID

DHCP relay agent information

Sub-option 1 – Circuit ID

The Circuit ID (CID) identifies the circuit or port from which a DHCP client request was sent. The Brocade ICX 6650 device uses this information to relay DHCP responses back to the proper circuit, for example, the port number on which the DHCP client request packet was received.

Brocade ICX 6650 devices support the General CID packet format. This simple format encodes the CID type, actual information length, VLAN ID, slot number, and port number. This format is compatible with the format used by other vendors’ devices. Figure 21 illustrates the general CID packet format.

FIGURE 21 General CID packet format

1

6

0

4

VLAN ID

Slot ID

Port

1 Byte 2 Bytes

Sub-option 2 – Remote ID

The Remote ID (RID) identifies the remote host end of the circuit (the relay agent). Brocade devices use the MAC address to identify itself as the relay agent. Figure 22 illustrates the RID packet format.

FIGURE 22 RID packet format

2

8

0

6

MAC Address

1 Byte

Sub-option 6 - Subscriber ID

The Subscriber ID (SID) is a unique identification number that enables an Internet Service Provider to:

•Identify a subscriber

•Assign specific attributes to that subscriber (for example, host IP address, subnet mask, and domain name server (DNS))

•Trigger accounting

Figure 23 illustrates the SID packet format.

FIGURE 23 SID packet format

6

N

ASCII String 1.....N

1 Byte

The second byte (N in Figure 23) is the length of the ASCII string that follows. The Brocade ICX 6650 device supports up to 50 ASCII characters.

290	Brocade ICX 6650 Security Configuration Guide
	53-1002601-01