- play_arrow AAA for Subscriber Management
- play_arrow AAA for Subscriber Management
- play_arrow RADIUS for Subscriber Management
- RADIUS Servers and Parameters for Subscriber Access
- Storage and Reporting of Interface Descriptions to Uniquely Identify Subscribers
- Session Options for Subscriber Access
- RADIUS NAS Port Attributes and Options
- RADIUS Logical Line Identification
- RADIUS Authentication and Accounting Basic Configuration
- RADIUS Reauthentication As an Alternative to RADIUS CoA for DHCP Subscribers
- Configuring RADIUS Reauthentication for DHCP Subscribers
- RADIUS Accounting for Subscriber Access
- Verifying and Managing Subscriber AAA Information
- Session Termination Causes and RADIUS Termination Cause Codes
- AAA Termination Causes and Code Values
- DHCP Termination Causes and Code Values
- L2TP Termination Causes and Code Values
- PPP Termination Causes and Code Values
- VLAN Termination Causes and Code Values
- play_arrow Domain Maps for Subscriber Management
- play_arrow Testing and Troubleshooting AAA
- play_arrow RADIUS Dictionary Files
- Junos OS Release 15.1 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 16.1 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 16.2 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 17.1 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 17.4 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 18.2 Subscriber Management RADIUS Dictionary [DCT]
- Junos OS Release 18.4 Subscriber Management RADIUS Dictionary [DCT]
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- play_arrow IPv6 for Subscriber Management
- play_arrow IPv6 for Subscriber Management
- Introduction to IPv6 Addresses
- Migration to IPv6 Using IPv4 and IPv6 Dual Stack
- IPv6 WAN Link Addressing with NDRA
- IPv6 WAN Link Addressing with DHCPv6 IA_NA
- Subscriber LAN Addressing with DHCPv6 Prefix Delegation
- WAN and LAN Addressing Using DHCPv6 IA_NA and DHCPv6 Prefix Delegation
- Designs for IPv6 Addressing in a Subscriber Access Network
- Dual-Stack Access Models in a DHCP Network
- Dual-Stack Access Models in a PPPoE Network
- Best Practices for Configuring IPv4 and IPv6 Dual Stack in a PPPoE Access Network
- Dual Stack for PPPoE Access Networks Using DHCP
- Dual Stack for PPPoE Access Networks Using NDRA
- IP Demultiplexing Interfaces on Packet-Triggered Subscriber Services
- Conservation of IPv4 Addresses for Dual-Stack PPP Subscribers Using On-Demand IPv4 Address Allocation
- Dual Stack Subscribers Monitoring and Management
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- play_arrow DHCPv6 for Subscriber Management
- play_arrow Packet Triggered Subscriber Services
- play_arrow Packet Triggered Subscriber Services
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- play_arrow Address-Assignment Pools for Subscriber Management
- play_arrow Address-Assignment Pools for Subscriber Management
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- play_arrow DNS Addresses for Subscriber Management
- play_arrow DNS Addresses for Subscriber Management
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- play_arrow M:N Subscriber Redundancy
- play_arrow Access Node Control Protocol and the ANCP Agent for Subscriber Services
- play_arrow Access Node Control Protocol and the ANCP Agent for Subscriber Services
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- play_arrow Diameter Base Protocol and its Applications
- play_arrow Diameter Base Protocol and its Applications
- Diameter Base Protocol
- Gx-Plus for Provisioning Subscribers
- 3GPP Policy and Charging Control for Wireline Provisioning and Accounting
- NASREQ for Authentication and Authorization
- JSRC for Subscriber Provisioning and Accounting
- JSRC and Subscribers on Static Interfaces
- Monitoring and Management Diameter Information
- Tracing Diameter Base Protocol Events for Troubleshooting
- Troubleshooting Diameter Networks
- Monitoring and Managing Static Subscriber Information
- Tracing Static Subscriber Events for Troubleshooting
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- play_arrow Configuration Statements and Operational Commands
Delaying DHCP Offer and Advertise Responses to Load Balance DHCP Servers
Load Balancing DHCP Local Servers by Delaying Responses to Clients
In a network environment with multiple DHCP local servers and numerous DHCP clients, you might want to load balance traffic by allowing some local servers to respond to specific clients while preventing other local servers from responding immediately to these clients. Starting in Junos OS Release 16.1R1, you can configure a client-specific delay in response on DHCP local servers. When a DHCPv4 client sends a discover message or a DHCPv6 client sends a solicit message to the server network, all the corresponding (Same family) DHCP servers on the network receive the request at the same time, but servers that are configured with a delay do not respond to the client until the delay timer expires.
When the delay timer expires, the local server sends an offer or advertise message to the client. If the client is already bound, that means that a different server, one that has either no delay or a shorter delay, responded with an offer or advertise message to the client. In this case the server configured with the delay releases the client.
However, if the client does not receive a response from any server, it sends a second discover or solicit message. If the configured server receives the second message from the client before the original delay times out, it immediately sends a response to the client. This behavior enables the configured server to act as a redundant or back-up server for the server that was intended to handle the client.
Table 1 lists the characteristics that you can use to identify DHCP clients for which responses are delayed and the corresponding DHCPv4 and DHCPv6 options you specify in the configuration.
Client Characteristic | DHCPv4 | DHCPv6 |
|---|---|---|
Agent Circuit ID—A string that identifies the local circuit between the client and the DHCP relay agent, uniquely identifying the particular client. | Option 82, suboption 1 | Option 18 |
Agent Remote ID—A string that uniquely identifies a client based on characteristics of the client, such as caller ID or user name. | Option 82, suboption 2 | Option 37 |
User Class Identifier—A string representing a class or group to which the client belongs. For example, different user classes might identify a marketing group versus an accounting group. | Option 77 | Option 15 |
Vendor Class Identifier—The IANA registered enterprise number for the vendor of the equipment running the client. | Option 60 | Option 16 |
Benefits to Delaying DHCP Local Server Response
Enable load to be distributed among many DHCP servers by causing certain clients to be preferably served by other servers.
Enable redundancy among servers by allowing a server to respond in the event the preferred server does not.
Configuring a Delay in Local Server Response to DHCP Discover and Solicit Messages
You can configure a DHCPv4 or DHCPv6 local server to delay responding to discover and solicit messages, respectively, from clients. The server responds to the client only when the delay timer expires. You can configure the delay at global, group, and interface levels. To determine which clients are sent a delayed response, configure the server to identify specific hexadecimal or ASCII strings received in the message from the client. The local server compares the configured string with the value received DHCP options in the client message and delays the response depending on whether the received value matches the configured value, does not match it, or starts with the configured value.
To configure a delayed response to an offer message received from a DHCPv4 client:
To configure a delayed response to an advertise message received from a DHCPv6 client:
Specify how long the DHCPv6 local server delays before responding to the client.
Specify the option received in the DHCPv6 advertise message that identifies the client to receive a delayed response.
Specify how to match the received option.
Match when the received ASCII or hexadecimal string is exactly the same as the configured string.
Match when the received ASCII or hexadecimal string is not exactly the same as configured string.
Match when the received ASCII or hexadecimal string starts with the configured string.
Change History Table
Feature support is determined by the platform and release you are using. Use Feature Explorer to determine if a feature is supported on your platform.
