Routing Protocol Support - Cisco ASR 5000 Series Administration Manual

▀ Features and Functionality - Base Software
The new feature utilizes the same concept as overlapping IP pools such that every overlapping NAS-IP address is giving
a unique next-hop address which is then bound to an interface that is bound to a unique VLAN, thereby allowing the
configuration to exist within the same context.
RADIUS access requests and accounting messages are forwarded to the next hop defined for that NAS-IP and it is then
up to the connected router's forward the messages to the RADIUS server. The next hop address determines the interface
and VLAN to use. Traffic from the server is identified as belonging to a certain NAS-IP by the port/VLAN
combination.
The number of Radius NAS-IP addresses that can be configured is limited by the number of loopback addresses that can
be configured.
Important:
Configuration Guide.

Routing Protocol Support

The system's support for various routing protocols and routing mechanism provides an efficient mechanism for ensuring
the delivery of subscriber data packets.
GGSN node supports Routing Protocol in different way to provide an efficient mechanism for delivery of subscriber
data.
The following routing mechanisms and protocols are supported by the system:
Static Routes: The system supports the configuration of static network routes on a per context basis. Network
routes are defined by specifying an IP address and mask for the route, the name of the interface in the currant
context that the route must use, and a next hop IP address.
Open Shortest Path First (OSPF) Protocol: A link-state routing protocol, OSPF is an Interior Gateway
Protocol (IGP) that routes IP packets based solely on the destination IP address found in the IP packet header
using the shortest path first. IP packets are routed "as is", meaning they are not encapsulated in any further
protocol headers as they transit the network.
Variable length subnetting, areas, and redistribution into and out of OSPF are supported.
OSPF routing is supported in accordance with the following standards:
Border Gateway Protocol version 4 (BGP-4): The system supports a subset of BGP (RFC-1771, A Border
Gateway Protocol 4 (BGP-4)), suitable for eBGP support of multi-homing typically used to support
geographically redundant mobile gateways, is supported.
EBGP is supported with multi-hop, route filtering, redistribution, and route maps. The network command is
support for manual route advertisement or redistribution.
BGP route policy and path selection is supported by the following means:
▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
For more information on VLAN support, refer VLANs chapter in System Enhanced Feature
RFC-1850, OSPF Version 2 Management Information Base, November 1995
RFC-2328, OSPF Version 2, April 1998
RFC-3101 OSPF-NSSA Option, January 2003
Prefix match based on route access list
AS path access-list
GGSN Support in GPRS/UMTS Wireless Data Services
OL-22944-02