Configuring a Fabric Over a Layer 3 Network



As described in previous sections, you can create a Netvisor ONE fabric over the management network or over in-band, i.e., between switches with direct (Layer 2) connectivity.


Another option is to establish Netvisor ONE fabric  over a Layer 3 network. Netvisor ONE supports this capability over a Layer 3 network running either the BGP or the OSPF routing protocol.


Before you can configure this feature on your network, make sure you configure BGP or OSPF routing on your switches. For more information on Layer 3 configuration,  refer to the Configuring Layer 3 Features section.


In a simple topology with a network of two BGP neighbors as in Figure 6-8.  Netvisor ONE uses in-band communication to establish TCP sessions between the two switches to exchange fabric messages.

 

 


Figure 6-8:  Example Network of Two BGP Neighbors Topology



To achieve the BGP-based configuration and establish fabric communication between the two switches, you must perform the following steps:


  1. Modify the in-band IP in the same subnet of in-band-nic-ip address.
  2. Create a vRouter on each switch.
  3. Setup BGP peering and redistribute routes.
  4. Setup up global static routes using the respective vRouter as the gateway. You must perform this step because the routes reside inside the vRouter table and each switch must have an appropriate route to reach the in-band network of another switch.
  5. Add global static route on switch B to reach switch A in-band network with switch B in-band-nic-ip as the gateway IP address.
  6. Then you can configure switch B to join the fabric previously created by switch A.


 

Use the following commands to accomplish the necessary configuration:


Creating a vRouter for Fabric Communication


Use the fabric-comm-vrouter-bgp-create command to create a vRouter for fabric communication.


This command has numerous options including the following:



name

Name of the fabric communication vRouter.

bgp-as

BGP Autonomous System number of the vrouter from 1 to 4294967295.

bgp-nic-vlan

Interface VLAN number between 0 and 4095. You can enable BGP over VLAN interface also.

bgp-redistribute

BGP route redistribution. The default value is connected.

bgp-max-paths

Maximum BGP paths.

bgp-ibgp-multipath

Number of IBGP multipath connections.

bgp-nic-ip

IP address of the peering interface.

bgp-nic-netmask netmask

BGP NIC netmask.

bgp-nic-linklocal ip-address

IPv6 link local address.

bgp-nic-vnet

Interface VLAN vNET.

bgp-nic-bd

Interface bridge domain.

bgp-nic-vlan-type

Interface VLAN type.

bgp-nic-l3-port

Layer 3 port

bgp-nic-mtu

Interface MTU

bgp-nic-if-nat-realm

NAT interface realm

in-band-nic-ip

IP address range of the in-band management interface.

remote-as

BGP remote AS number from 1 to 4294967295

neighbor

IP address of the BGP neighbor.

 

 

The BGP protocol reserves Autonomous System (AS) numbers 64512–65534 for private use and the example below uses some of the private AS numbers.


This dedicated CLI performs the majority of the actions in the logical steps 1-4 described in the Configuring a Fabric Over a Layer 3 Network section above. However, it does not change the inband IP address or create the fabric.


After creating the fabric, the root switch, Switch A, does not have to specify the fabric network in the switch configuration, but the switch must create a route to the other inband network on the switch with the fabric-in-band-network-create command.


Switch B, a non-root switch, does need to specify the fabric network by using the fabric-network parameter:


See an example on how to establish fabric communication between two switches (switch A and switch B) detailed in steps 1 through 6 above.


Switch A


CLI (network-admin@switch) > switch-setup-modify in-band-ip 12.1.1.1/24


CLI (network-admin@switch) > fabric-comm-vrouter-bgp-create name vrouter-a bgp-nic-l3-port 10 bgp-as 65001 bgpnic-ip 192.169.0.5/30 in-band-nic-ip 12.1.1.10/24 remote-as 65002 neighbor 192.169.0.6 bgp-redistribute connected fabric-network 12.1.1.0/24


CLI (network-admin@switch) > fabric-in-band-network-create network 12.1.2.1/24


Switch B


CLI (network-admin@switch) > switch-setup-modify in-band-ip 12.1.2.1/24


CLI (network-admin@switch) > fabric-comm-vrouter-bgp-create name vrouter-b bgp-nic-l3-port 20 bgp-as 65002 bgpnic-ip 192.169.0.6/30 in-band-nic-ip 12.1.2.10/24 remote-as 65001 neighbor 192.169.0.5 fabric-network 12.1.1.0/24 bgp-redistribute connected fabric network 12.1.2.0/24


CLI (network-admin@switch) > switch-route-create network 12.1.1.0/24 gateway-ip 12.1.2.10


CLI (network-admin@switch) > fabric-join switch-ip 12.1.1.1


CLI (network-admin@switch) > Joined fabric myfabric. Restarting nvOS...