The dropped traffic situation can occur because of the way some DSLAMs create the
giaddr that is sent to the DHCP external server application. Some Ethernet DSLAMs
use a DHCP relay implementation that inserts giaddr values and relay agent options
in DHCP packets that are received from end users. The intent is that this information
is provided to a DHCP server, which uses the values to determine the configuration
parameters for the subscriber.
However, when the DHCP external server application receives the giaddr from an
Ethernet DSLAM, the application installs the subscriber access route with the Ethernet
DSLAM’s IP address as the next hop, This operation results in the subscriber-destined
traffic being incorrectly sent to the Ethernet DSLAM, which cannot process the traffic.
To avoid dropping the traffic in this situation, use the
ip set dhcp-external
disregard-giaddr-next-hop
command to configure the DHCP external server
application to ignore the giaddr when determining the next hop for the subscriber
access routes. The E Series router then uses Address Resolution Protocol (ARP) to
discover the subscriber’s IP address and sends the traffic to the learned IP address.
To configure the DHCP external server application to ignore the giaddr when
determining the next hop for the subscriber access routes:
■
Issue the
ip dhcp-external disregard-giaddr-next-hop
command from Global
Configuration mode:
host1(config)#
ip dhcp-external disregard-giaddr-next-hop
Related Topics
■
ip dhcp-external disregard-giaddr-next-hop
Configuring the DHCP External Server to Support the Creation of Dynamic
Subscriber Interfaces
You can configure the DHCP external server to support the creation of dynamic
subscriber interfaces. This configuration requires that the user’s DHCP control traffic
and data traffic traverse the same client-facing ingress port on the E Series router.
You must use the
ip dhcp-external auto-configure
command within a specific virtual
router context.
To configure the DHCP external server to support the creation of dynamic subscriber
interfaces:
■
Issue the
ip dhcp-external auto-configure
command from Global Configuration
mode:
host1(config)#
ip dhcp-external auto-configure
To configure the DHCP external server to support the creation of dynamic subscriber
interfaces built over dynamic VLANs that are based on the agent-circuit-id option
(suboption 1) of the option 82 field in DHCP messages, include the
agent-circuit-identifier
keyword.
524
■
Configuring the DHCP External Server to Support the Creation of Dynamic Subscriber Interfaces
JUNOSe 11.0.x Broadband Access Configuration Guide
Summary of Contents for JUNOSE 11.0.X MULTICAST ROUTING
Page 6: ...vi...
Page 28: ...xxviii Table of Contents JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 36: ...xxxvi List of Tables JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 42: ...2 Managing Remote Access JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 204: ...164 Managing RADIUS and TACACS JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 292: ...252 Monitoring RADIUS Relay Server JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 336: ...296 RADIUS Client Terminate Reasons JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 368: ...328 Managing L2TP JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 444: ...404 PPP Accounting Statistics JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 494: ...454 Managing DHCP JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 510: ...470 DHCP Local Server Configuration Tasks JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 556: ...516 Configuring DHCP Relay Proxy JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 616: ...576 Managing the Subscriber Environment JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 674: ...634 Managing Subscriber Services JUNOSe 11 0 x Broadband Access Configuration Guide...
Page 767: ...Part 7 Index Index on page 729 Index 727...
Page 768: ...728 Index JUNOSe 11 0 x Broadband Access Configuration Guide...