3Com 4800G Series, Configuration Manual

Page: 188 / 1246

188 C
HAPTER
22: DLDP C
ONFIGURATION
■
MD5 authentication. In this mode, before sending a packet, the sending side
encrypts the user configured password using MD5 algorithm, assigns the digest
to the Authentication field, and sets the Authentication type field to 2. The
receiving side checks the values of the two fields of received DLDP packets and
drops the packets with the two fields conflicting with the corresponding local
configuration.
DLDP implementation
1 On a DLDP-enabled link that is in up state, DLDP sends DLDP packets to the peer
device and processes the DLDP packets received from the peer device. DLDP
packets sent vary with DLDP states. Table 33 lists DLDP states and the
corresponding packets.
n
When a device transits from a DLDP state other than Inactive state or Disable state
to Initial state, it sends Flush packets.
2 A received DLDP packet is processed as follows.
■
In any of the three authentication modes, the packet is dropped if it fails to
pass the authentication.
■
The packet is dropped if the setting of the interval for sending Advertisement
packets it carries conflicts with the corresponding local setting.
■
Other processes.
Table 33 DLDP packet types and DLDP states
DLDP state Type of DLDP packets sent
Active Advertisement packet with RSY tag
Advertisement Normal Advertisement packet
Probe Probe packet
Disable Disable packet and RecoverProbe packet
Table 34 Procedures for processing different types of DLDP packets
Packet type Processing procedure
Advertisement
packet with RSY
tag Retrieving the
neighbor
information. If the corresponding neighbor entry does not exist,
creates the neighbor entry, triggers the Entry timer,
and transits to Probe state.
If the corresponding neighbor entry already exists,
resets the Entry timer and transits to Probe state.
Normal
Advertisement
packet
Retrieves the
neighbor
information. If the corresponding neighbor entry does not exist,
creates the neighbor entry, triggers the Entry timer,
and transits to Probe state.
If the corresponding neighbor entry already exists,
resets the Entry timer.
Flush packet Determines
whether or not
the local port is in
Disable state. If yes, no process is performed.
If not, removes the corresponding neighbor entry (if
any).
Probe packet Retrieves the
neighbor
information. If the corresponding neighbor entry does not exist,
creates the neighbor entry, transits to Probe state,
and returns Echo packets.
If the corresponding neighbor entry already exists,
resets the Entry timer and returns Echo packets.