Allworx PowerFlex P810, User Manual

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PowerFlex
8/24/48 Port GbE PoE Managed Switch User’s Guide
Term Definition
task. This means that a new computer can be added to a network without the
hassle of manually assigning it a unique IP address.
DHCP Relay
Forwards and transfers DHCP messages between the clients and the server
when not on the same subnet domain.
The DHCP option 82 enables a DHCP relay agent to insert specific
information into a DHCP request packets when forwarding client DHCP
packets to a DHCP server and remove the specific information from a DHCP
reply packets when forwarding server DHCP packets to a DHCP client. The
DHCP server can use this information to implement IP address or other
assignment policies. Specifically the option works by setting two sub-options:
Circuit ID (option 1) and Remote ID (option2). The Circuit ID sub-option is
supposed to include information specific to which circuit the request came in
on. The Remote ID sub-option was designed to carry information relating to
the remote host end of the circuit.
The definition of Circuit ID in the switch is 4 bytes in length and the format is
"vlan_id" "module_id" "port_no". The parameter of "vlan_id" is the first two
bytes represent the VLAN ID. The parameter of "module_id" is the third byte
for the module ID (in standalone switch it always equal 0, in stackable switch
it means switch ID). The parameter of "port_no" is the fourth byte and it
means the port number.
The Remote ID is 6 bytes in length, and the value is equal the DHCP relay
agents MAC address.
DHCP Snooping
Blocks intruders 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
An acronym for Domain Name System. It stores and associates many types
of information with domain names. Most importantly, DNS translates human-
friendly domain names and computer hostnames into computer-friendly IP
addresses. For example, the domain name www.example.com might translate
to 192.168.0.1.
DoS
An acronym for Denial of Service. In a denial-of-service (DoS) attack, an
attacker attempts to prevent legitimate users from accessing information or
services. By targeting at network sites or network connection, an attacker may
be able to prevent network users from accessing email, web sites, online
accounts (banking, etc.), or other services that rely on the affected computer.
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.
DSCP
An acronym for Differentiated Services Code Point. It is a field in the header
of IP packets for packet classification purposes.
E
EEE
An abbreviation for Energy Efficient Ethernet defined in IEEE 802.3az.
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Revised: October 30, 2013
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