Option
Number and Description
User Port Stacking
Option 230
Set the stacking option variable to provide DHCP server stack-port detail when the DHCP offer is set.
End
Option 255
Signals the last option in the DHCP packet.
Assign an IP Address using DHCP
The following section describes DHCP and the client in a network.
When a client joins a network:
1
The client initially broadcasts a
DHCPDISCOVER
message on the subnet to discover available DHCP servers. This message includes
the parameters that the client requires and might include suggested values for those parameters.
2
Servers unicast or broadcast a
DHCPOFFER
message in response to the DHCPDISCOVER that offers to the client values for the
requested parameters. Multiple servers might respond to a single DHCPDISCOVER; the client might wait a period of time and then
act on the most preferred offer.
3
The client broadcasts a
DHCPREQUEST
message in response to the offer, requesting the offered values.
4
After receiving a DHCPREQUEST, the server binds the clients’ unique identifier (the hardware address plus IP address) to the
accepted configuration parameters and stores the data in a database called a binding table. The server then broadcasts a
DHCPACK
message, which signals to the client that it may begin using the assigned parameters.
5
When the client leaves the network, or the lease time expires, returns its IP address to the server in a
DHCPRELEASE
message.
There are additional messages that are used in case the DHCP negotiation deviates from the process previously described and shown in
the illustration below.
DHCPDECLINE
A client sends this message to the server in response to a DHCPACK if the configuration parameters are
unacceptable; for example, if the offered address is already in use. In this case, the client starts the configuration
process over by sending a DHCPDISCOVER.
DHCPINFORM
A client uses this message to request configuration parameters when it assigned an IP address manually rather
than with DHCP. The server responds by unicast.
DHCPNAK
A server sends this message to the client if it is not able to fulfill a DHCPREQUEST; for example, if the requested
address is already in use. In this case, the client starts the configuration process over by sending a
DHCPDISCOVER.
Figure 33. Client and Server Messaging
Dynamic Host Configuration Protocol (DHCP)
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Содержание S4048T-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 11 2 1 ...
Страница 148: ...Figure 10 BFD Three Way Handshake State Changes 148 Bidirectional Forwarding Detection BFD ...
Страница 251: ...Dell Control Plane Policing CoPP 251 ...
Страница 363: ... RPM Synchronization GARP VLAN Registration Protocol GVRP 363 ...
Страница 511: ...Figure 64 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 511 ...
Страница 512: ...Figure 65 Inspecting Configuration of LAG 10 on ALPHA 512 Link Aggregation Control Protocol LACP ...
Страница 515: ...Figure 67 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 515 ...
Страница 516: ...Figure 68 Inspecting LAG 10 Using the show interfaces port channel Command 516 Link Aggregation Control Protocol LACP ...
Страница 558: ...Figure 84 Configuring Interfaces for MSDP 558 Multicast Source Discovery Protocol MSDP ...
Страница 559: ...Figure 85 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 559 ...
Страница 560: ...Figure 86 Configuring PIM in Multiple Routing Domains 560 Multicast Source Discovery Protocol MSDP ...
Страница 564: ...Figure 88 MSDP Default Peer Scenario 2 564 Multicast Source Discovery Protocol MSDP ...
Страница 565: ...Figure 89 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 565 ...
Страница 729: ...protocol spanning tree pvst no disable vlan 300 bridge priority 4096 Per VLAN Spanning Tree Plus PVST 729 ...
Страница 841: ...Figure 115 Single and Double Tag TPID Match Service Provider Bridging 841 ...
Страница 842: ...Figure 116 Single and Double Tag First byte TPID Match 842 Service Provider Bridging ...