Table 101: Router Configuration and Transmission of DHCP Reply Packets
(continued)
Router Behavior if
Broadcast Flag Not Set
Router Behavior if
Broadcast Flag Set
Layer 2 Unicast
Replies
Broadcast Flag
Replies
DHCP relay and DHCP relay
proxy broadcast DHCP
reply packets to clients. For
information about
exceptions to this behavior
for DHCP relay proxy, see
“Behavior for Bound Clients
and Address Renewals” on
page 514
.
DHCP relay and DHCP
relay proxy broadcast
DHCP reply packets to
clients. For information
about exceptions to this
behavior for DHCP relay
proxy, see “Behavior for
Bound Clients and Address
Renewals” on page 514
.
Disabled (off)
Disabled (off)
Preventing DHCP Relay from Installing Host Routes by Default
The Address Resolution Protocol (ARP) performs spoof checking on all incoming ARP
requests by default. For each incoming packet, ARP does a route lookup on the source
IP address to determine the interface on which that IP address was routed. ARP then
verifies that the interface on which the packet was received matches the routed
interface. If the interface on which the packet was received does not match the routed
interface, the router drops the packet.
When you configure applications such as DHCP relay that automatically install routes,
you must ensure that the routes are correctly installed for your configuration. DHCP
relay installs host routes by default, which is required in certain configurations to
enable address renewals from the DHCP server to work properly. However, the
default installation of host routes might cause a conflict when you configure DHCP
relay with static subscriber interfaces. To avoid these configuration conflicts, use the
set dhcp relay inhibit-access-route-creation
command to prevent DHCP relay from
installing host routes by default. The command enforces consistent state of the route
and client database.
In relay mode, this command removes all installed host routes from IP, deletes all
host routes from mirrored storage and NVS, and stops accumulating host route
information.
In relay proxy mode, this command removes all installed host routes from IP, deletes
all NVS client data, and stops installing host routes for newly bound clients in IP.
However, it does preserve the client data in mirrored storage and continues
preservation of newly bound clients in mirrored storage.
The
no set dhcp relay inhibit-access-route-creation
command enforces consistent
state of the route and client database. In relay proxy mode, after the unified ISSU is
completed and normal operations resume, this command installs a host route for all
existing bound clients in IP and saves it in NVS.
Configuration Example—Preventing Installation of Host Routes
This example describes a sample procedure for configuring multiple subscribers over
a particular static subscriber interface (ip53001 in this example)—you might use
494
■
Configuring DHCP Relay and BOOTP Relay
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...