Brocade Network OS Administrator’s Guide v4.1.1 - Manual (Page 450)

In LLDP the link discovery is achieved through the exchange of link-level information between two link
partners. The link-level information is refreshed periodically to reflect any dynamic changes in link-
level parameters. The basic format for exchanging information in LLDP is in the form of a type, length,
value (TLV) field.
LLDP keeps a database for both local and remote configurations. The LLDP standard currently
supports three categories of TLVs. Brocade’s LLDP implementation adds a proprietary Brocade
extension TLV set. The four TLV sets are described as follows:
• Basic management TLV set — This set provides information to map the Layer 2 topology and
includes the following TLVs:
‐ Chassis ID TLV — Provides the ID for the switch or router where the port resides. This is a
mandatory TLV.
‐ Port description TLV — Provides a description of the port in an alphanumeric format. If the
LAN device supports RFC-2863, the port description TLV value equals the "ifDescr" object.
This is a mandatory TLV.
‐ System name TLV — Provides the system-assigned name in an alphanumeric format. If
the LAN device supports RFC-3418, the system name TLV value equals the "sysName"
object. This is an optional TLV.
‐ System description TLV — Provides a description of the network entity in an alphanumeric
format. This includes system name, hardware version, operating system, and supported
networking software. If the LAN device supports RFC-3418, the value equals the
"sysDescr" object. This is an optional TLV.
‐ System capabilities TLV — Indicates the primary functions of the device and whether
these functions are enabled in the device. The capabilities are indicated by two octets. The
first octet indicates Other, Repeater, Bridge, WLAN AP, Router, Telephone, DOCSIS cable
device, and Station, respectively. The second octet is reserved. This is an optional TLV.
‐ Management address TLV — Indicates the addresses of the local switch. Remote
switches can use this address to obtain information related to the local switch. This is an
optional TLV.
• IEEE 802.1 organizational TLV set — This set provides information to detect mismatched settings
between local and remote devices. A trap or event can be reported once a mismatch is detected.
This is an optional TLV. This set includes the following TLVs:
‐ Port VLANID TLV — Indicates the port VLAN ID (PVID) that is associated with an
untagged or priority tagged data frame received on the VLAN port.
‐ PPVLAN ID TLV — Indicates the port- and protocol-based VLAN ID (PPVID) that is
associated with an untagged or priority tagged data frame received on the VLAN port. The
TLV supports a "flags" field that indicates whether the port is capable of supporting port-
and protocol-based VLANs (PPVLANs) and whether one or more PPVLANs are enabled.
The number of PPVLAN ID TLVs in a Link Layer Discovery Protocol Data Unit (LLDPDU)
corresponds to the number of the PPVLANs enabled on the port.
‐ VLAN name TLV — Indicates the assigned name of any VLAN on the device. If the LAN
device supports RFC-2674, the value equals the "dot1QVLANStaticName" object. The
number of VLAN name TLVs in an LLDPDU corresponds to the number of VLANs enabled
on the port.
‐ Protocol identity TLV — Indicates the set of protocols that are accessible at the device's
port. The protocol identity field in the TLV contains a number of octets after the Layer 2
address that can enable the receiving device to recognize the protocol. For example, a
device that wishes to advertise the spanning tree protocol includes at least eight octets:
802.3 length (two octets), LLC addresses (two octets), 802.3 control (one octet), protocol
ID (two octets), and the protocol version (one octet).
• IEEE 802.3 organizational TLV set — This is an optional TLV set. This set includes the following
TLVs:
Configuring LLDP
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