HP 6125G HP 6125G & 6125G/XG Blade Switches Layer 2 - LAN Switching Co - Page 153

• On a GARP-enabled network, each port maintains its own Hold, Join, and Leave timers, but only one LeaveAll timer is maintained on each device. This LeaveAll timer applies to all ports on the device. • The value ranges for the Hold, Join, Leave, and LeaveAll timers are dependent on one another. See Table 19 for their dependencies. • Set the LeaveAll timer greater than any Leave timer and not smaller than its default value, 1000 centiseconds. Each time a LeaveAll timer expires, a network-wide re-join occurs. • A device can send LeaveAll messages at the interval set by its LeaveAll timer or the LeaveAll timer of another device on the network, whichever is smaller. This is because each time a device on the network receives a LeaveAll message, it resets its LeaveAll timer. GARP PDU format Figure 45 GARP PDU format Ethernet frame DA SA Length DSAP SSAP Ctrl GARP PDU Protocol ID Message 1 ... Message n End mark Attribute type Attribute list Attribute 1 ... Attribute n End mark Attribute length Attribute event Attribute value As shown in Figure 45, GARP PDUs are encapsulated in IEEE 802.3 Ethernet frames. Table 18 GARP PDU fields Field Protocol ID Message End mark Attribute type Attribute list Attribute Attribute length Description Protocol identifier for GARP One or multiple messages, each of which contains an attribute type and an attribute list Indicates the end of a GARP PDU Defined by the GARP application Contains one or multiple attributes Consists of an attribute length, an attribute event, and an attribute value Length of an attribute, inclusive of the attribute length field Value 0x0001 N/A 0x00 0x01 for GVRP, which indicates the VLAN ID attribute N/A N/A 2 to 255 (in bytes) 144