Configuring DHCP Proxy Clients
DHCP proxy client support enables the router to obtain an IP address from a DHCP
server for a remote PPP client. Each virtual router (acting as a DHCP proxy client)
can query up to five DHCP servers.
For PPP users, the router acts as a DHCP client to obtain an address for the user.
This is referred to as DHCP proxy.
The process for PPP users is as follows:
1.
The remote user dials in, and the client requests RADIUS authentication.
2.
The AAA server on the router sends a request to the DHCP proxy client on the
router for an IP address to be assigned to the remote user’s host.
3.
The proxy client assumes the role of DHCP client and sends a discovery message
to each DHCP server.
4.
One or more of the DHCP servers responds with an offer message containing
an IP address.
5.
The proxy client determines which offer to accept and sends a message to that
DHCP server requesting that IP address.
6.
The DHCP server responds to the proxy client with an acknowledgment message.
7.
The proxy client passes the IP address to the authentication, authorization, and
accounting (AAA) server on the router, and the AAA server returns the address
to PPP. PPP then assigns the address to the remote host. The new IP address is
included when the router next updates its routing table.
Dynamic IP addresses are
leased
to the remote host for a specific period of time,
which can range from minutes to days. At the halfway point in the lease period, the
proxy client requests an extension from the DHCP server on behalf of the remote
host. The lease is extended for a period specified in the acknowledgment (ACK)
message returned by the DHCP server—typically equal to the original lease. If the
DHCP server returns a negative acknowledgment (NAK) message to the proxy client,
the proxy client notifies the server on the router that the extension has been denied.
The AAA server logs out the remote host and frees the IP address for reuse.
When a remote host disconnects, the AAA server notifies the proxy client that the
IP address is available for reuse. The proxy client informs the DHCP server, which
can now reassign that IP address.
For additional information on managing client bindings, see “Viewing and Deleting
DHCP Client Bindings” on page 460.
To configure a proxy client from Global Configuration mode:
1.
Specify the address of the DHCP server that will provide IP addresses for remote
hosts. You can specify a maximum of five DHCP servers.
host1(config)#
ip dhcp-server 10.6.128.10
458
■
Configuring DHCP Proxy Clients
JUNOSe 11.0.x Broadband Access Configuration Guide
Содержание JUNOSE 11.0.X MULTICAST ROUTING
Страница 6: ...vi...
Страница 28: ...xxviii Table of Contents JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 36: ...xxxvi List of Tables JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 42: ...2 Managing Remote Access JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 204: ...164 Managing RADIUS and TACACS JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 274: ...234 CLI Commands Used to Modify RADIUS Attributes JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 292: ...252 Monitoring RADIUS Relay Server JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 336: ...296 RADIUS Client Terminate Reasons JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 368: ...328 Managing L2TP JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 408: ...368 Configuring the Weighted Load Balancing Method JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 444: ...404 PPP Accounting Statistics JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 492: ...452 Monitoring Operational Status within the Current VR Context JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 494: ...454 Managing DHCP JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 510: ...470 DHCP Local Server Configuration Tasks JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 528: ...488 Configuring the Router to Work with the SRC Software JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 556: ...516 Configuring DHCP Relay Proxy JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 616: ...576 Managing the Subscriber Environment JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 632: ...592 Subscriber Management Configuration Examples JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 636: ...596 Monitoring Active IP Subscribers Created by Subscriber Management JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 672: ...632 Monitoring Active IP Subscribers Created by Subscriber Management JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 674: ...634 Managing Subscriber Services JUNOSe 11 0 x Broadband Access Configuration Guide...
Страница 767: ...Part 7 Index Index on page 729 Index 727...
Страница 768: ...728 Index JUNOSe 11 0 x Broadband Access Configuration Guide...