9
General operating principles
FIGURE 17
Each LLDPDU consists of an untagged Ethernet header and a sequence of short, variable length
information elements known as TLVs.
TLVs have Type, Length, and Value fields, where:
•
•
•
TLV support
This section lists the LLDP TLV support.
LLDP TLVs
There are two types of LLDP TLVs, as specified in the IEEE 802.3AB standard:
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•
256
LLDPDU packet format
Chassis ID
Port ID
TLV
TLV
M
M
M = mandatory TLV (required for all LLDPDUs)
Type identifies the kind of information being sent
Length indicates the length (in octets) of the information string
Value is the actual information being sent (for example, a binary bit map or an alpha-numeric
string containing one or more fields).
Basic Management TLVs consist of both optional general system information TLVs as well as
mandatory TLVs.
Mandatory TLVs cannot be manually configured. They are always the first three TLVs in the
LLDPDU, and are part of the packet header.
General system information TLVs are optional in LLDP implementations and are defined by the
Network Administrator.
Brocade devices support the following Basic Management TLVs:
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Chassis ID (mandatory)
•
Port ID (mandatory)
•
Time to Live (mandatory)
•
Port description
•
System name
•
System description
•
System capabilities
•
Management address
•
End of LLDPDU
Organizationally-specific TLVs are optional in LLDP implementations and are defined and
encoded by individual organizations or vendors. These TLVs include support for, but are not
limited to, the IEEE 802.1 and 802.3 standards and the TIA-1057 standard.
Brocade devices support the following Organizationally-specific TLVs:
Time to
Optional
...
Live TLV
TLV
M
Optional
End of
TLV
LLDPDU TLV
M
BigIron RX Series Configuration Guide
53-1001986-01