Configuring Local Address Servers; Local Address Pool Ranges; Figure 1: Local Address Pool Hierarchy - Juniper JUNOSE SOFTWARE 11.0.X - BROADBAND ACCESS CONFIGURATION GUIDE 4-1-2010 Configuration Manual

JUNOSe 11.0.x Broadband Access Configuration Guide

Configuring Local Address Servers

The local address server allocates IP addresses from a pool of addresses stored locally
on the router. You can optionally configure shared local address pools to obtain
addresses from a DHCP local address pool that is in the same virtual router. Addresses
are provided automatically to client sessions requiring an IP address from a virtual
router that is configured to use a local address pool.
A local address server is defined in the context of a virtual router. You create a local
address server when you configure the first local pool. Local address servers exist
as long as the virtual router exists or until you remove them by deleting all configured
pools.
Figure 1 on page 54 illustrates the local address pool hierarchy. Multiple local address
server instances, one per virtual router. can exist. Each local address server can have
one or more local address pools. Each pool can contain a number of IP addresses
that are available for allocation and used by clients, such as PPP sessions.

Figure 1: Local Address Pool Hierarchy

Local Address Pool Ranges

As shown in Figure 1 on page 54, each local address pool is named and contains
ranges of sequentially ordered IP addresses. These addresses are allocated when the
AAA server makes a request for an IP address.
If a local address pool range is exhausted, the next range of addresses is used. If all
pool ranges are exhausted, you can configure a new range to extend or supplement
the existing range of addresses, or you can create a new pool. The newly created
pool range is then used for future address allocation. If addresses allocated from the
first pool range are released, then subsequent requests for addresses are taken from
the first pool range.
Addresses are assigned sequentially from a range within a pool. If a range has no
addresses available, the next range within that pool is used. If a pool has no addresses
available, the next configured pool is used, unless a specific pool is indicated.
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Configuring Local Address Servers