78 lines
6.0 KiB
HTML
78 lines
6.0 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="Relay agents and routers" />
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<meta name="abstract" content="You might need to use a DHCP relay agent in your network; sometimes a router is sufficient. You can use both a DHCP relay agent and a router to efficiently and securely transfer data throughout the network." />
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<meta name="description" content="You might need to use a DHCP relay agent in your network; sometimes a router is sufficient. You can use both a DHCP relay agent and a router to efficiently and securely transfer data throughout the network." />
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<meta name="DC.Relation" scheme="URI" content="rzakgscenario6.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzakgplanningdemands.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 2004, 2006" />
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Relay agents and routers</title>
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</head>
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<body id="rzakgconceptrelayrouter"><a name="rzakgconceptrelayrouter"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Relay agents and routers</h1>
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<div><p>You might need to use a DHCP relay agent in your network; sometimes
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a router is sufficient. You can use both a DHCP relay agent and a router to
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efficiently and securely transfer data throughout the network.</p>
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<p>Initially, DHCP clients broadcast their DISCOVER packets because they do
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not know what network they are connected to. In some networks, the DHCP server
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might not be on the same LAN as the client. Therefore, it is necessary to
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forward the client's broadcast DHCP packets to the LAN where the DHCP server
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is. Some routers are configured to forward DHCP packages. If your router supports
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DHCP packet forwarding, that is all you need. However, many routers do not
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forward packets that have a destination IP address of the broadcast address
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(DHCP packets). In this case, if the router cannot forward DHCP packets, then
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the LAN must have a BOOTP/DHCP relay agent to forward the DHCP packets to
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the LAN with the DHCP server. Refer to Example: DHCP and PPP
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profile on different iSeries™ servers for a sample network using a relay
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agent and a router.</p>
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<p>In either case, because the DHCP server is on a separate network, your
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clients will need to have the router option (option 3) defined that specifies
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the IP address of the router that connects their network to the network with
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the DHCP server.</p>
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<p>In these scenarios, if you do not use a BOOTP/DHCP relay agent, you will
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need to add a DHCP server to the other LAN to serve those clients. To help
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you decide how many DHCP servers to have in your network, refer to Network
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topology considerations.</p>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakgconceptparent.htm" title="DHCP interacts with clients and works in a network.">DHCP concepts</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><a href="rzakgplanningdemands.htm" title="You can plan for most of the DHCP setup by looking at your network topology, the devices on the network (for example, routers), and how you want to support your clients in DHCP.">Network topology considerations</a></div>
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<div><a href="rzakgproblemnoip.htm" title="Problems might occur if the clients cannot receive an IP address or the configuration information. An IP address is leased to a client through a four-step process between the client and the DHCP server.">Problem: Clients are not receiving an IP address or their configuration information</a></div>
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</div>
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<div class="reltasks"><strong>Related tasks</strong><br />
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<div><a href="rzakgconfiguringinterface.htm" title="This topic explains what software you need to use to configure the iSeries DHCP server. It also includes instructions to work with the DHCP configuration, use the DHCP Server Monitor, and set up a DHCP/BOOTP relay agent.">Configure the DHCP server and BOOTP/DHCP relay agent</a></div>
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</div>
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<div class="relref"><strong>Related reference</strong><br />
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<div><a href="rzakgconceptinteract.htm" title="A client gets the DHCP information from the server, and specific messages are sent between the client and the server. DHCP obtains and returns leases.">DHCP client-server interaction</a></div>
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<div><a href="rzakgscenario6.htm" title="You can learn how to set up two iSeries servers as the network DHCP server and a DHCP/BOOTP relay agent for two LANs and remote dial-in clients.">Example: DHCP and PPP profile on different iSeries servers</a></div>
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</div>
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</div>
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</body>
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</html>
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