DHCP OTHERS
- The DHCP server validates its authorization in AD DS every hour. It uses LDAP protocol [MS-ADTS] for the purpose of communicating with the Active Directory and validating whether it is authorized to serve IP addresses.
DHCPINFORM: DHCPInform is a DHCP message used by DHCP clients to obtain DHCP options. While PPP remote access clients do not use DHCP to obtain IP addresses for the remote access connection, Windows 2000 and Windows 98 remote access clients use the DHCPInform message to obtain DNS server IP addresses, WINS server IP addresses, and a DNS domain name.
The DHCPInform message is sent after the IPCP negotiation is concluded. The DHCPInform message received by the remote access server is then forwarded to a DHCP server. The remote access server forwards DHCPInform messages only if it has been configured with the DHCP Relay Agent.
Integration between DHCP and DNS:
How does DHCP and BOOTP handle multiple subnets? For the situations where there is more than one LAN, each with its own subnet number, there are two ways. First of all, you can set up a seperate server on each subnet. Secondly, a feature of some routers known as “BOOTP forwarding” to forward DHCP or BOOTP requests to a server on another subnet and to forward the replies back to the client. The part of such a router (or server acting as a router) that does this is called a “BOOTP forwarding agent”. Typically you have to enable it on the interface to the subnet to be served and have to configure it with the IP address of the DHCP or BOOTP server. On a Cisco router, the address is known as the “UDP Helper Address”.
How can I prevent unauthorized laptops from using a network that uses DHCP for dynamic addressing?
This would have to be done using a mechanism other than DHCP. DHCP does not prevent other clients from using the addresses it is set to hand out nor can it distinguish between a computer’s permanent MAC address and one set by the computer’s user. DHCP can impose no restrictions on what IP address can use a particular port nor control the IP address used by any client.
Can DHCP work with AppleTalk or IPX?
No, it is too tied to IP. Furthermore, they don’t need it since they have always had automated mechanisms for assigning their own network addresses.
Dhcpnak Message? If the Server is unable to satisfy the DHCPREQUEST message (The requested network address has been allocated) the Server Should sent DHCPNAK message to client. It can also be Sent if client’s notion of network address is incorrect (Client has moved to new subnet) or client’s lease expired.
Dhcp decline message: It is Sent by Client to server indicating network address is already in use (already assigned to another device)
APIPA Address range:
What Is Bootp?BOOTP (bootstrap protocol) is a host configuration protocol. It is developed before DHCP.
How Is It Different Than Bootp Or Rarp?
Event ID for
Lease expired
IP full
DHCP CLUSTER
Links 2 Managing Lease Durations
Consider the ratio between connected computers and available IP addresses. For example, if there are 40 systems sharing a Class C address (with 254 available addresses), the demand for reusing addresses is low. A long lease time, such as two months, would be appropriate in such a situation. However, if 230 computers share the same address pool, demand for available addresses is greater, and a lease time of a few days or weeks is more appropriate.