Copyright © 2010, Juniper Networks, Inc.
Known Behavior
19
Release 11.1.1
If you are upgrading the JunosE Software on the router from any of these releases,
you must explicitly issue the
ip dhcp-external recreate-subscriber-interface
command to configure the router to continue to delete and re-create the DHCP
client’s dynamic subscriber interface.
z
DHCP external server may not be able to bind all DHCP clients when all of the
following conditions exist:
−
DHCP external server and either DHCP relay or relay proxy are configured in
separate virtual routers on an E320 router.
−
The client-facing and server-facing interfaces for DHCP external server and
either DHCP relay or relay proxy are configured on the same ES2 4G LM.
−
DHCP external server is configured to create dynamic subscriber interfaces.
When these three conditions exist simultaneously, the ES2 4G LM may not be able to
successfully process all DHCP packets. Although all clients may get bounded in
DHCP relay or relay proxy, some clients may not get bounded in DHCP external
server. (In a production environment it is highly unlikely for conditions 1 and 2 to exist
because stand-alone DHCP external server is normally configured for a DHCP relay in
a different chassis.)
Work-around
: You can eliminate this issue by modifying any one of these conditions.
For example, this issue does not exist with any of the following configuration
modifications:
−
Configure DHCP external server and either DHCP relay or relay proxy in the same
virtual router.
−
Configure the client-facing and server-facing interfaces for DHCP external server
and either DHCP relay or relay proxy on the same ES2 10G LM instead of the
same ES2 4G LM.
−
Configure the client-facing and server-facing interfaces for DHCP external server
and either DHCP relay or relay proxy on separate ES2 4G LMs.
z
DHCP NAK packets are sent from a different VLAN than the one on which the renew
request is received on a router that is configured with dynamic VLANs, DHCP local
server, and automatically created dynamic subscriber interfaces. This behavior
occurs only after a link flap has taken place.
Dynamic Interfaces
z
Dynamic IPv6 interfaces over static PPP interfaces are not supported.
Ethernet
z
The hashing algorithm that selects the LAG member link is associated with the IP
address of the subscriber client to support QoS. Consequently, a particular flow is
always hashed to the same link. When a member link is removed from a LAG bundle,
traffic rate is disrupted and traffic flow is reduced. When the link goes down and then
comes back up, the traffic flow is automatically redistributed.
Informational Note:
The DHCP external server application is unsupported in JunosE
Release 8.2.1 and JunosE Release 8.2.2.
