The following provides instructions on how to configure the fabric on an installed full POD with two leaf and two spine switches. The fabric needs to be configured to forward traffic between the different components of the POD. More info about how to configure the fabric can be found here.
Each leaf switch on the fabric corresponds to a separate IP subnet. The recommended configuration is a POD with two leaves; the leaf1 subnet is 10.6.1.0/24 and the leaf2 subnet is 10.6.2.0/24.
##Configure the Fabric: Overview
A service running on the head node can produce an ONOS network configuration to control the leaf and spine network fabric. This configuration is generated by querying ONOS for the known switches and compute nodes and producing a JSON structure that can be posted to ONOS to implement the fabric.
The configuration generator can be invoked using the cord generate command, which prints the configuration to standard output.
##Remove Stale ONOS Data
Before generating a configuration you need to make sure that the instance of ONOS controlling the fabric doesn't contain any stale data and that has processed a packet from each of the switches and computes nodes.
ONOS needs to process a packet because it does not have a mechanism to automatically discover the network elements. Thus, to be aware of a device on the network ONOS needs to first receive a packet from it.
To remove stale data from ONOS, the ONOS CLI wipe-out command can be used:
ssh -p 8101 onos@onos-fabric wipe-out -r -j please Warning: Permanently added '[onos-fabric]:8101,[10.6.0.1]:8101' (RSA) to the list of known hosts. Password authentication Password: (password rocks) Wiping intents Wiping hosts Wiping Flows Wiping groups Wiping devices Wiping links Wiping UI layouts Wiping regions
NOTE: When prompted, use password "rocks".
To ensure ONOS is aware of all the switches and the compute nodes, you must have each switch "connected" to the controller and let each compute node ping over its fabric interface to the controller.
##Connect the Fabric Switches to ONOS
If the switches are not already connected, the following command on the head node CLI will initiate a connection.
for s in $(cord switch list | grep -v IP | awk '{print $3}'); do
ssh -i ~/.ssh/cord_rsa -qftn root@$s ./connect -bg 2>&1 > $s.log
done
You can verify ONOS has recognized the devices using the following command:
ssh -p 8101 onos@onos-fabric devices Warning: Permanently added '[onos-fabric]:8101,[10.6.0.1]:8101' (RSA) to the list of known hosts. Password authentication Password: id=of:0000cc37ab7cb74c, available=true, role=MASTER, type=SWITCH, mfr=Broadcom Corp., hw=OF-DPA 2.0, sw=OF-DPA 2.0, serial=, driver=ofdpa, channelId=10.6.0.23:58739, managementAddress=10.6.0.23, protocol=OF_13 id=of:0000cc37ab7cba58, available=true, role=MASTER, type=SWITCH, mfr=Broadcom Corp., hw=OF-DPA 2.0, sw=OF-DPA 2.0, serial=, driver=ofdpa, channelId=10.6.0.20:33326, managementAddress=10.6.0.20, protocol=OF_13 id=of:0000cc37ab7cbde6, available=true, role=MASTER, type=SWITCH, mfr=Broadcom Corp., hw=OF-DPA 2.0, sw=OF-DPA 2.0, serial=, driver=ofdpa, channelId=10.6.0.52:37009, managementAddress=10.6.0.52, protocol=OF_13 id=of:0000cc37ab7cbf6c, available=true, role=MASTER, type=SWITCH, mfr=Broadcom Corp., hw=OF-DPA 2.0, sw=OF-DPA 2.0, serial=, driver=ofdpa, channelId=10.6.0.22:44136, managementAddress=10.6.0.22, protocol=OF_13
NOTE: This is a sample output that won’t necessarily reflect your output
NOTE: When prompt, use password "rocks".
NOTE: It may take a few seconds for the switches to initialize and connect to ONOS
##Configure the Compute Nodes
Before connecting to ONOS, the compute nodes must be configured with data plane IP addresses appropriate to their subnet. The POD build process assigns data plane IP addresses to nodes, but it is not subnet-aware and so IP addresses must be changed for compute nodes on the leaf2 switch.
###Assign IP addresses
Log into the XOS GUI an click on Nodes. For nodes connected to leaf2, change the dataPlaneIp attribute to a unique IP address on the 10.6.2.0/24 subnet and click Save.
XOS will communicate the new IP address to the ONOS VTN app, which will change it on the nodes. Once the switches are connected to ONOS as part of the fabric configuration process (see subsequent sections), log into each compute node and verify that br-int has the new IP address:
ip addr list br-int
###Add Routes to Fabric Subnets
Routes must be manually configured on the compute nodes so that traffic between nodes on different leaves will be forwarded via the local spine switch.
Run commands of this form on each compute node:
sudo ip route add <remote-leaf-subnet> via <local-spine-ip>
In this configuration, on the nodes attached to leaf1 (including the head node), run:
sudo ip route add 10.6.2.0/24 via 10.6.1.254
Likewise, on the compute nodes attached to leaf2, run:
sudo ip route add 10.6.1.0/24 via 10.6.2.254
NOTE: it’s strongly suggested to add it as a permanent route to the nodes, so the route will still be there after a reboot
##Configure NAT Gateway on the Head Node (Optional)
In a production POD, a vRouter is responsible for providing connectivity between the fabric and the Internet, but this requires configuring BGP peering between the vRouter and an upstream router. In environments where this is not feasible, it is possible to use the head node as a NAT gateway for the fabric by configuring some routes on the head node and in ONOS as described below.
###Add Routes for Fabric Subnets
The default POD configuration uses the 10.7.1.0/24 subnet for vSG traffic to the Internet, and 10.8.1.0/24 for other Internet traffic. Add routes on the head node to forward traffic to these subnets into the fabric:
sudo route add -net 10.7.1.0/24 gw 10.6.1.254 sudo route add -net 10.8.1.0/24 gw 10.6.1.254
###Add Default Route to Head Node from Fabric
ONOS must be configured to forward all outgoing Internet traffic to the head node's fabric interface, which by default has IP address 10.6.1.1:
ssh -p 8101 onos@onos-fabric route-add 0.0.0.0/0 10.6.1.1
NOTE: When prompted, use password "rocks".
##Connect Compute Nodes to ONOS
To make sure that ONOS is aware of the compute nodes, the following commands will send a ping over the fabric interface on the head node and each compute node.
ping -c 1 10.6.1.254
for h in $(cord prov list | grep "^node" | awk '{print $2}'); do
ssh -i ~/.ssh/cord_rsa -qftn ubuntu@$h ping -c 1 10.6.1.254;
done
NOTE: It is fine if the
pingcommand fails; the purpose is to register the node with ONOS.
You can verify ONOS has recognized the nodes using the following command:
ssh -p 8101 onos@onos-fabric hosts Warning: Permanently added '[onos-fabric]:8101,[10.6.0.1]:8101' (RSA) to the list of known hosts. Password authentication Password: id=00:16:3E:DF:89:0E/None, mac=00:16:3E:DF:89:0E, location=of:0000cc37ab7cba58/3, vlan=None, ip(s)=[10.6.1.1], configured=false id=3C:FD:FE:9E:94:28/None, mac=3C:FD:FE:9E:94:28, location=of:0000cc37ab7cba58/4, vlan=None, ip(s)=[10.6.1.2], configured=false
NOTE: When prompt, use password rocks
##Generate the Network Configuration
To modify the fabric configuration for your environment, generate on the head node a new network configuration using the following commands:
cd /opt/cord_profile && \
cp fabric-network-cfg.json{,.$(date +%Y%m%d-%H%M%S)} && \
cord generate > fabric-network-cfg.json
##Load Network Configuration
Once these steps are done load the new configuration into XOS, and restart the apps in ONOS:
###Install Dependencies
sudo pip install httpie
###Delete Old Configuration
http -a onos:rocks DELETE http://onos-fabric:8181/onos/v1/network/configuration/
###Load New Configuration
http -a onos:rocks POST http://onos-fabric:8181/onos/v1/network/configuration/ < /opt/cord_profile/fabric-network-cfg.json
###Restart ONOS Apps
http -a onos:rocks DELETE http://onos-fabric:8181/onos/v1/applications/org.onosproject.segmentrouting/active http -a onos:rocks POST http://onos-fabric:8181/onos/v1/applications/org.onosproject.segmentrouting/active
To verify that XOS has pushed the configuration to ONOS, log into ONOS in the onos-fabric VM and run netcfg:
$ ssh -p 8101 onos@onos-fabric netcfg
Password authentication
Password:
{
"devices": {
"of:0000480fcfaeee2a": {
"segmentrouting": {
"name": "device-480fcfaeee2a",
"ipv4NodeSid": 100,
"ipv4Loopback": "10.6.0.103",
"routerMac": "48:0f:cf:ae:ee:2a",
"isEdgeRouter": true,
"adjacencySids": []
}
},
"of:0000480fcfaede26": {
"segmentrouting": {
"name": "device-480fcfaede26",
"ipv4NodeSid": 101,
"ipv4Loopback": "10.6.0.101",
"routerMac": "48:0f:cf:ae:de:26",
"isEdgeRouter": true,
"adjacencySids": []
}
},
...
NOTE: When prompt, use password "rocks"
Once the new ONOS configuration is active, the fabric interface on each node should be reachable from the other nodes. From each compute node, ping the IP address of head node's fabric interface (e.g., 10.6.1.1).
Sometimes ping fails for various reasons. Reconnecting switches to ONOS often solves the problem:
Log into the switch from the head node:
ssh root@SWITCH_IP
NOTE: Switch IPs can be found by running "cord switch list" on the head node
Kill the current connection and restart a new one:
./killit ./connect -bg
Sometimes restarting ONOS segmentrouting app also helps:
http -a onos:rocks DELETE http://onos-fabric:8181/onos/v1/applications/org.onosproject.segmentrouting/active http -a onos:rocks POST http://onos-fabric:8181/onos/v1/applications/org.onosproject.segmentrouting/active