Siemens S223 Benutzerhandbuch

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UMN:CLI                                                                                                                                                              User  Manual 
SURPASS hiD 6615 S223/S323 R1.5 
250                                                                         A50010-Y3-C150-2-7619 
8.8.3.3 
Deleting DHCP Lease Database 
To delete a DHCP lease database, use the following command. 
Command Mode 
Description 
clear ip dhcp leasedb
 A.B.C.D/M
Deletes a DHCP lease database a specified subnet. 
clear ip dhcp leasedb pool
 
POOL
 
Deletes a DHCP lease database of a specified DHCP 
pool. 
clear ip dhcp leasedb all 
Enable 
Global 
Deletes the entire DHCP lease database. 
 
8.8.4 DHCP 
Relay 
Agent 
A DHCP relay agent is any host that forwards DHCP packets between clients and servers. 
The DHCP relay agents are used to forward DHCP requests and replies between clients 
and servers when they are not on the same physical subnet. The DHCP relay agent for-
warding is distinct from the normal forwarding of an IP router, where IP datagrams are 
switched between networks somewhat transparently. 
By contrast, DHCP relay agents receive DHCP messages and then generate a new 
DHCP message to send out on another interface. The DHCP relay agent sets the gate-
way address and, if configured, adds the DHCP option 82 information in the packet and 
forwards it to the DHCP server. The reply from the server is forwarded back to the client 
after removing the DHCP option 82 information. 
Relay Agent 1
DHCP Server
Relay Agent 2
Subnet 1
Subnet 2
*PC= DHCP Client
 
Fig. 8.32 
Example of DHCP Relay Agent 
 
To activate/deactivate the DHCP function in the system, use the following command. 
Command Mode 
Description 
service dhcp
 
Activates the DHCP function in the system. 
no service dhcp 
Global 
Deactivates the DHCP function in the system.