Managing TLV Units

Each TLV unit has properties that you can further configure with specific values. When that TLV unit is enabled as an LLDP agent's property, then that TLV unit is advertised in the network only with the specified values. Consider, for example, the TLV value syscapab which advertises a system's capabilities. These capabilities can potentially include support for routers, bridges, repeaters, telephones, and other devices. However, you can set syscapab so that only those capabilities that are actually supported in your specific system, such as routers and bridges, are advertised.

The procedure for managing TLVs depends on whether you are configuring global TLVs or per-agent TLVs.

Global TLVs apply to all the LLDP agents on the system. The following table displays the global TLV values and their corresponding possible configurations.

Table 16-2 Global TLVs and Their Properties

TLV units that cannot have global values are managed at the LLDP agent level. With per-agent TLV units, the values that you provide are used when the TLV unit is enabled for transmission by a specific LLDP agent.

The following table displays the TLV values and their corresponding possible configurations for an LLDP agent.

Table 16-3 Per-Agent TLV Units and Their Properties

The following procedure shows how to define global TLV values. For a discussion about how to define per-agent TLV units, see Data Center Bridging.

How to Define Global TLV Values

This procedure shows how to provide global values for specific TLV units. To set global TLV values, you use the llpadm set-tlvprop subcommand.

1. Configure the appropriate TLV property to contain the values that you want to advertise.

   For reference, see Table 16-2.

   # lldpadm set-tlvprop -p tlv-property=value[,value,value,...] tlv

2. (Optional) Display the values of the property that you have just configured.

   # lldpadm show-tlvprop

Example 16-3 Specifying the System's Capabilities and the Management IP Address

This example accomplishes two objectives:

• Provides specific information about the system's capabilities to be advertised in the LLDP packet. To achieve this objective, both supported and enabled properties of the syscapab TLV unit must be configured.

• Provides the management IP address that is used in the advertisement.

# llpdadm set-tlvprop -p supported=bridge,router,repeater syscapab
# llpdadm set-tlvprop -p enabled=router syscapab
# llpdadm set-tlvprop -p ipaddr=192.168.1.2 mgmtaddr
# llpdadm show-tlvprop
TLVNAME    PROPERTY   PERM  VALUE        DEFAULT         POSSIBLE
syscapab   supported  rw    bridge,      bridge,router,  other,router,
                            router,      station         repeater,bridge,
                            repeater                     wlan-ap,telephone,
                                                         docis-cd,station,
                                                         cvlan,svlan,tpmr
syscapab   enabled    rw    router       none            bridge,router,
                                                         repeater
mgmtaddr   ipaddr     rw    192.162.1.2  none            --

Data Center Bridging

To support Fibre Channel over Ethernet (FCoE) traffic, the LLDP implementation in Oracle Solaris includes data center bridging (DCB) support.

In networks that use traditional Ethernet for traffic exchange, an ongoing risk is that packets might be dropped when the network is busy. A key requirement for FCoE traffic is that no packet drops can occur during transmission. With support for Data Center Bridging Exchange (DCBx), the priority—based flow control (PFC) TLV, and the Application TLV, dropped packets are avoided.

PFC extends the standard PAUSE frame to include the priority information for packets. Typically, a PAUSE frame is sent on a link when traffic is heavy to enable the receiving end to process packets it has already received. With PFC, instead of transmitting a PAUSE frame to stop all traffic on the link, traffic is paused according to priorities defined for the packets. A PFC frame can be sent for the priority for which traffic needs to be paused. The sender stops traffic for that specific priority, while traffic for other priorities are unaffected. After a specified time, another PFC frame is sent to signal that the paused traffic can resume.

PFC configuration information is exchanged between peer stations by means of DCBx. If peers in a traffic exchange have matching PFC configurations, then PFC can pause or resume traffic transmission as needed. To enable different packets to be assigned different priorities, the Application TLV is used to define priority information. If peers have mismatching PFC configurations, the PFC TLV can be customized to accept the other peer's configuration, as shown in the procedure that follows.

Data Center Bridging is a specific case to illustrate how to configure per-agent TLV units as explained in Managing TLV Units.

How to Set Per-Agent TLV Values

This procedure shows how to set TLV values at the LLDP agent level by using the llpadm set-agenttlvprop subcommand.

1. Configure the appropriate TLV property to contain the values that you want to advertise by a given LLDP agent.

   For reference, see Table 16-3.

   # lldpadm set-agenttlvprop -p tlv-property[+|-]=value[,value,value,...] -a agent tlv-name

2. (Optional) Display the values of the property that you have just configured.

   # lldpadm show-agenttlvprop

Example 16-4 Enabling the LLDP Agent to Accept Information and Specifying TLV Application Priorities

This example shows how the pfc as well as the appln TLV values are customized. The TLV units in this example specify how DCB operates for FCoE traffic. The system is configured to accept the peer's PFC configuration in case the local configuration does not match the peer's configuration. The example also shows how the priority is set for the LLDP agent's application TLV.

# lldpadm set-agenttlvprop -p willing=on -a net0 pfc
# lldpadm set-agenttlvprop -p apt=8906/1/4 -a net0 appln
# lldpadm show-agenttlvprop
AGENT   TLVNAME   PROPERTY   PERM   VALUE      DEFAULT   POSSIBLE
net0    pfc       willing    rw     on         off       on,off
net0    appln     apt        rw     8906/1/4   --        --