HP 2610-PWR - Manual (Page 291)

IP Routing Features
Configuring DHCP Relay
■ Circuit ID: This nonconfigurable subfield identifies the port number
of the physical port through which the routing switch received a given
DHCP client request, and is necessary to identify if you want to
configure an Option 82 DHCP server to use the Circuit ID to select a
DHCP policy to assign to clients connected to the port. This number
is the identity of the inbound port. On ProCurve fixed-port switches,
the port number used for the Circuit ID is always the same as the
physical port number shown on the front of the switch. On ProCurve
chassis switches, where a dedicated, sequential block of internal port
numbers are reserved for each slot, regardless of whether a slot is
occupied, the circuit ID for a given port is the sequential index number
for that port position in the slot. (To view the Index number assign­
ments for ports in the routing switch, use the
walkmib ifname
command.)
For example, the circuit ID for a client connected to port 11 on a ProCurve
2650-PWR (J8165A) switch is “11”. However, the Circuit ID for port B11
on a ProCurve 5304xl (J4850A) is “37”. (See Figure 7-13, below.)
In this example, the 5304xl has a 4-port module
installed in slot “A” and a 24-port module installed in
slot “B”. Thus, the first port numbers in the listing are
the Index numbers reserved for slot “A”. The first Index
port number for slot “B” is “27”, and the Index port
number for port B11 (and therefore the Circuit ID
number) is “37”.
The Index (and Circuit ID) number for port B11
on a 5304xl routing switch.
Figure 7-13.Using Walkmib To Determine the Circuit ID for a Port on a ProCurve Chassis
7-33