Configuring Dhcp Ipv4 Profile Proxy Class - Cisco ASR 9000 Series Configuration Manual

Enabling DHCP Proxy
BNG procures IP leases from the DHCP server and keeps it in its pool. When the client needs to renew its
lease, it unicasts the lease renewal request directly to the BNG, assuming it to be the server. BNG renews the
lease by allocating the lease from its lease pool.
This way the DHCP proxy splits the lease management process into two phases:
• Server to Proxy (Proxy Lease)
• Proxy to Client (Client lease)
The two phase lease management has these features:
• Shorter client lease times and longer proxy lease times.
• High frequency lease management (renews) at network edge.
• Low frequency lease management (renews) at centralized server.
The benefits of DHCP proxy are:
• Reduced traffic between BNG and DHCP server.
• Quicker client response to network outages.
Configuring DHCP proxy on BNG involves these phases:
• Creating a proxy profile. The profile contains various proxy settings. These settings are applied when
the profile is attached to an interface. To create a proxy profile, see
Proxy Class, on page 88
• Specifying circuit-ID for an interface. The circuit-ID is used by the proxy to identify the circuit in which
the DHCP request was received. Later, DHCP proxy uses it for relaying DHCP responses back to the
proper circuit. The circuit-ID is defined for an interface. To define it, see
an Interface, on page
• Attaching proxy profile to an interface. See,

Configuring DHCP IPv4 Profile Proxy Class

Perform this task to define DHCP.
Cisco ASR 9000 Series Aggregation Services Router Broadband Network Gateway Configuration Guide,
Release 4.2.x
88
◦ Specifying client lease period. The client should renew the lease before the completion of this time
period, otherwise the lease expires. To specify the client lease period within a proxy profile, see
Configuring the Client Lease Time, on page
◦ Specifying remote-ID. The remote-ID is used by the proxy to identify the host that had sent the
DHCP request. To define a remote-id within a proxy profile, see
page 91.
90.
Establishing Subscriber Sessions
Configuring DHCP IPv4 Profile
92.
Configuring a Remote-ID, on
Attaching a Proxy Profile to an Interface, on page 94
Configuring a Circuit-ID for
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