Appendix
carry information relating to the remote host end of the circuit.
"vlan_id" "module_id" "port_no". The parameter of "vlan_id" is the first two bytes
the
eans
byte and it means the port
number.
The definition of Circuit ID in the switch is 4 bytes in length and the format is
represent the VLAN ID. The parameter of "module_id" is the third byte for
module ID (in standalone switch it always equal 0, in stackable switch it m
switch ID). The parameter of "port_no" is the fourth
The Remote ID is 6 bytes in length, and the value is equal the DHCP relay agents
MAC address.
DHCP Snooping
DHCP Snooping is used to block intruder on the untrusted ports of the switch
device when it tries to intervene by injecting a bogus DHCP reply packet to a
legitimate conversation between the DHCP client and server.
DNS
DNS is an acronym for
D
omain
N
ame
S
ystem. It stores and associates many
types of information with domain names. Most importantly, DNS translates
human-friendly domain names and comput
er hostnames into computer-friendly IP
addresses. For example, the domain name www.example.com might translate to
192.168.0.1.
Dotted Decimal Notation
Dotted Decimal Notation refers to a method of writing IP addresses using decimal
numbers and dots as separators between octets.
An IPv4 dotted decimal address has the form x.y.z.w, where x, y, z, and w are
decimal numbers between 0 and 255.
Drop Precedence Level
Every incoming frame is classified to a Drop Precedence Level (DP level), which
e
level of 0
is used throughout the device for providing congestion control guarantees to th
frame according to what was configured for that specific DP level. A DP
(zero) corresponds to 'Committed' (Green) frames and a DP level of 1 or
higher corresponds to 'Discard Eligible' (Yellow) frames.
DSCP
DSCP is an acronym for
D
ifferentiated
S
ervices
C
ode
P
oint. It is a field in the
header of IP packets for packet classification purposes.
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