Users Guide

Discovering Network Devices 915
ISDP interoperates with the Cisco-proprietary CDP protocol and is most
effective in an environment that contains many Cisco devices.
IPDT is used to track the state of the attached hosts and maintain up-to-date
MAC/IPv4 address bindings. The MAC/IPv4 bindings are used to populate
the RADIUS Framed-IP-Address attribute transmitted in RADIUS Access-
Request packets and to update the source IP address in Dynamic ACLs.
IPDT does not send ARP probes for entries already present in the ARP table
until they age out and ARP packets are exchanged. When IPDT is enabled for
the first time, it may take up to 20 minutes (or the configured ARP timeout)
for the IPDT table to populate.
Default IDSP and LLDP Values
ISDP and LLDP are globally enabled on the switch and enabled on all ports
by default. By default, the switch transmits and receives LLDP information
on all ports. LLDP-MED is enabled on all ports by default. The switch sends
LLDP frames using destination MAC address 01:80:c2:00:00:0e and
EtherType 0x88CC. The switch recognizes LLDP frames addressed to MAC
addresses 01:80:c2:00:00:0e, 01:80:c2:00:00:00, 01:80:c2:00:00:03, and
EtherType 0x88CC. Frames addressed to other group MAC addresses are
discarded.
Table 22-1 summarizes the default values for ISDP.
Table 22-2 summarizes the default values for LLDP.
Table 22-1. ISDP Defaults
Parameter Default Value
ISDP Mode Enabled (globally and on all ports)
ISDPv2 Mode Enabled (globally and on all ports)
Message Interval 30 seconds
Hold Time Interval 180 seconds
Device ID none
Device ID Format Capability Serial Number, Host Name
Device ID Format Host Name