Configuring Dynamic Routing Using BGP
This section describes how to configure the dynamic routing using BGP.
Configuring AS and BGP Router IP Address
To configure the AS and IP address for the BGP router, use the following commands:
config
router bgp local_as_number
exit
exit
NOTES:
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router bgp local_as_number —Specify the identification number for the AS for the BGP router.
In a inter-rack redundancy deployment, you need to configure two Autonomous Systems (AS).
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One AS for leaf and spine.
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Second AS for both racks: Rack-1 and Rack-2.
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Configuring BGP Service Listening IP Address
To configure the BGP service listening IP address, use the following commands:
config
router bgp local_as_number
interface interface_name
exit
exit
NOTES:
-
router bgp local_as_number —Specify the identification number for the AS for the BGP router.
-
interface interface_name —Specify the name of the interface.
Configuring BGP Neighbors
To configure the BGP neighbors, use the following commands:
config
router bgp local_as_number
interface interface_name
neighbor neighbor_ip_address remote-as as_number
exit
exit
NOTES:
-
router bgp local_as_number —Specify the identification number for the AS for the BGP router.
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interface interface_name —Specify the name of the interface.
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neighbor neighbor_ip_address —Specify the IP address of the neighbor BGP router.
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remote-as as_number —Specify the identification number for the AS.
Configuring Bonding Interface
To configure the bonding interface related to the interfaces, use the following commands:
config
router bgp local_as_number
interface interface_name
bondingInterface interface_name
exit
exit
NOTES:
-
router bgp local_as_number —Specify the identification number for the AS for the BGP router.
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interface interface_name —Specify the name of the interface.
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bondingInterface interface_name —Specify the related bonding interface for an interface. If the bonding interface is active, then the BGP gives a higher preference to the interface-service by providing a lower MED value.
Configuring Learn Default Route
If the user configures specific routes on their system and they need to support all routes, then they must set the learnDefaultRoute as true.
Note | This configuration is optional. |
To configure the Learn Default Route, use the following commands:
config
router bgp local_as_number
learnDefaultRoute true/false
exit
exit
NOTES:
-
router bgp local_as_number —Specify the identification number for the AS for the BGP router.
-
learnDefaultRoute true/false —Specify the option to enable or disable the learnDefaultRoute parameter. When set to true, BGP learns default route and adds it in the kernel space. By default, it is false.
Configuring BGP Port
To configure the Port number for a BGP service, use the following commands:
config
router bgp local_as_number
loopbackPort port_number
exit
exit
NOTES:
-
router bgp local_as_number —Specify the identification number for the AS for the BGP router.
-
loopbackPort port_number —Specify the port number for the BGP service. The default value is 179.
Policy Addition
The BGP speaker pods learns many route information from its neighbors. However, only a few of them are used for supporting the outgoing traffic. This is required for egress traffic handling only, when cnSGW-CSMF is sending information outside to AMF/PCF. Routes are filtered by configuring import policies on the BGP speakers and is used to send learned routes to the protocol pods.
A sample CLI code for policy addition and the corresponding descriptions for the parameters are shown below.
$bgp policy <policy_Name> ip-prefix 209.165.200.225 subnet 16 masklength-range 21..24 as-path-set “^65100”
Element | Description | Example | Optional |
---|---|---|---|
as-path-set | AS path value | “^65100” | Yes |
ip-prefix | Prefix value | “209.165.200.225/16” | Yes |
masklength-range | Range of length | “21..24” | Yes |
interface | Interface to set as source IP (default is VM IP) | eth0 | Yes |
gateWay | Change gateway of incoming route | 209.165.201.30 | Yes |
modifySourceIp | Modify source ip of incoming route Default value is False. |
true | Yes |
isStaticRoute | Flag to add static IP address into kernel route Default value is False. |
true | Yes |