Руководство По Устранению Ошибки для Cisco Cisco Packet Data Gateway (PDG)
IP Pool Sharing Protocol
▀ Overview
▄ Cisco ASR 5000 Series Enhanced Feature Configuration Guide
OL-22982-01
Overview
The IP Pool Sharing Protocol (IPSP) is a protocol that system-based HA services can use during an offline-software
upgrade to avoid the assignment of duplicate IP addresses to sessions while allowing them to maintain the same address,
and to preserve network capacity.
upgrade to avoid the assignment of duplicate IP addresses to sessions while allowing them to maintain the same address,
and to preserve network capacity.
In order for IPSP to be used, at least two system-based HAs with identical configurations must be present on the same
LAN. IPSP uses a primary & secondary model to manage the IP pools between the HAs. When used, this protocol
ensures the following:
LAN. IPSP uses a primary & secondary model to manage the IP pools between the HAs. When used, this protocol
ensures the following:
In-progress sessions can be handed-off to the secondary HA when an offline-software upgrade is being
performed on the primary and receive the same IP address that it was originally assigned.
New sessions can be redirected to the secondary HA when an offline-software upgrade is being performed on the
primary and receive a non-duplicate IP address.
The protocol is enabled at the interface level. Each system-based HA must have an IPSP-enabled interface configured in
the same context as the HA service for this protocol to function properly.
the same context as the HA service for this protocol to function properly.
Primary HA Functionality
The primary HA is the system that is to be upgraded. It performs the following functions for IPSP:
Queries the pool information from the secondary HA; the pool configurations on both HAs must be identical
Assigns an IP address or address block to the secondary HA when requested by the secondary HA; the primary
HA releases sessions if they have an IP address requested by the secondary
For graceful termination conditions (e.g. an administrative user issues the
command), sends a
termination message to the secondary HA causing it to assume the responsibilities of the primary HA until the
primary is available again.
primary is available again.
Sends a trap when the number of calls drops to zero after starting IPSP
Secondary HA Functionality
The secondary HA is the system that takes over Mobile IP sessions from the primary HA that is being upgraded. It
performs the following functions for IPSP:
performs the following functions for IPSP:
Locks the IP pools until it receives an address or address block assignment from the primary HA; it unlocks the
IP pools after busying out the addresses that are not assigned to it
Processes address requests for sessions that are within the address block assigned to it