Cisco Cisco IOS Software Release 12.2(27)SBC
BGP Support for IP Prefix Import from Global Table into a VRF Table
How to Import IP Prefixes from Global Table into a VRF Table
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Cisco IOS Release: Multiple releases (see the Feature History table)
Black Hole Routing
This feature can be configured to support Black Hole Routing (BHR). BHR is method that allows the
administrator to block undesirable traffic, such as traffic from illegal sources or traffic generated by a
Denial of Service (DoS) attack, by dynamically routing the traffic to a dead interface or to a host
designed to collect information for investigation, mitigating the impact of the attack on the network.
Prefixes are looked up, and packets that come from unauthorized sources are blackholed by the ASIC at
line rate.
administrator to block undesirable traffic, such as traffic from illegal sources or traffic generated by a
Denial of Service (DoS) attack, by dynamically routing the traffic to a dead interface or to a host
designed to collect information for investigation, mitigating the impact of the attack on the network.
Prefixes are looked up, and packets that come from unauthorized sources are blackholed by the ASIC at
line rate.
Classifying Global Traffic
This feature can be used to classify global IP traffic based on physical location or class of service. Traffic
is classified based on administration policy and then imported into different VRFs. On a college campus,
for example, network traffic could be divided into an academic network and residence network traffic, a
student network and faculty network, or a dedicated network for multicast traffic. After the traffic is
divided along administration policy, routing decisions can be configured with the MPLS VPN—VRF
Selection using Policy Based Routing or the MPLS VPN—VRF Selection Based on Source IP address
features.
is classified based on administration policy and then imported into different VRFs. On a college campus,
for example, network traffic could be divided into an academic network and residence network traffic, a
student network and faculty network, or a dedicated network for multicast traffic. After the traffic is
divided along administration policy, routing decisions can be configured with the MPLS VPN—VRF
Selection using Policy Based Routing or the MPLS VPN—VRF Selection Based on Source IP address
features.
How to Import IP Prefixes from Global Table into a VRF Table
This section contains the following tasks:
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Defining IPv4 IP Prefixes to Import
IPv4 unicast or multicast prefixes are defined as match criteria for the import route map using standard
Cisco IOS filtering mechanisms. This task uses an IP access-list and an IP prefix-list.
Cisco IOS filtering mechanisms. This task uses an IP access-list and an IP prefix-list.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
access-list access-list-number {deny | permit} source [source-wildcard] [log]
4.
ip prefix-list prefix-list-name [seq seq-value] {deny network/length | permit network/length} [ge
ge-value] [le le-value]
ge-value] [le le-value]