Brocade Communications Systems Brocade ICX 6650 6650 - Manual (Page 310)

290 Brocade ICX 6650 Security Configuration Guide
53-1002601-01
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
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
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
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.
1 Byte 2 Bytes
1 6 0 4 VLAN ID Slot ID Port
1 Byte
2 8 0 6 MAC Address
1 Byte
6 N ASCII String 1.....N