Lab: OpenFlow Multiple Path at kvm in GNS3

Enables per-flow load distribution

Increases the robustness
Increases efficiency
Simplifies management of layer 2 network resources

Various multipath techniques

Layer 3: ECMP – Equal Cost Multi-Path
Layer 2: LAG – Ethernet Link Aggregation Groups
Layer 1: VCAT – Virtual conCATenation

Environment

Group Table - Group Types

Required: all
Execute all buckets in the group. This group is used for multicast or broadcast forwarding. The packet is effectively cloned for each bucket; one packet is processed for each bucket of the group. If a bucket directs a packet explicitly out the ingress port, this packet clone is dropped. If the controller writer wants to forward out the ingress port, the group must include an extra bucket which includes an output action to the OFPP_IN_PORT reserved port.
Optional: select
Execute one bucket in the group. Packets are processed by a single bucket in the group, based on a switch-computed selection algorithm (e.g. hash on some user-configured tuple or simple round robin). All configuration and state for the selection algorithm is external to OpenFlow. The selection algorithm should implement equal load sharing and can optionally be based on bucket weights. When a port specified in a bucket in a select group goes down, the switch may restrict bucket selection to the remaining set (those with forwarding actions to live ports) instead of dropping packets destined to that port. This behavior may reduce the disruption of a downed link or switch.
Required: indirect
Execute the one defined bucket in this group. This group supports only a single bucket. Allows multiple flow entries or groups to point to a common group identifier, supporting faster, more efficient convergence (e.g. next hops for IP forwarding). This group type is effectively identical to an all group with one bucket.
Optional: fast failover
Execute the first live bucket. Each action bucket is associated with a specific port and/or group that controls its liveness. The buckets are evaluated in the order defined by the group, and the first bucket which is associated with a live port/group is selected. This group type enables the switch to change forwarding without requiring a round trip to the controller. If no buckets are live, packets are dropped. This group type must implement a liveness mechanism (see 6.6).

Steps

On all switches. Wipe the actions=NORMAL flow.

sudo ovs-ofctl del-flows brLAN
sudo ovs-vsctl set bridge brLAN protocols=OpenFlow13
sudo ovs-vsctl set Interface eth2 ofport_request=102
sudo ovs-vsctl set Interface eth3 ofport_request=103
sudo ovs-vsctl set Interface eth4 ofport_request=104
sudo ovs-vsctl set Interface eth5 ofport_request=105
sudo ovs-vsctl set Interface eth6 ofport_request=106
sudo ovs-vsctl set Interface eth7 ofport_request=107
sudo ovs-vsctl set Interface eth8 ofport_request=108
sudo ovs-vsctl set Interface eth9 ofport_request=109
sudo ovs-ofctl -O OpenFlow13 show brLAN
OFPT_FEATURES_REPLY (OF1.3) (xid=0x2): dpid:00000000abff3402
n_tables:254, n_buffers:256
capabilities: FLOW_STATS TABLE_STATS PORT_STATS QUEUE_STATS
OFPST_PORT_DESC reply (OF1.3) (xid=0x3):
 102(eth2): addr:00:00:ab:ff:34:02
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 103(eth3): addr:00:00:ab:ff:34:03
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 104(eth4): addr:00:00:ab:ff:34:04
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 105(eth5): addr:00:00:ab:ff:34:05
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 106(eth6): addr:00:00:ab:ff:34:06
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 107(eth7): addr:00:00:ab:ff:34:07
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 108(eth8): addr:00:00:ab:ff:34:08
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 109(eth9): addr:00:00:ab:ff:34:09
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
 LOCAL(brLAN): addr:00:00:ab:ff:34:02
     config:     0
     state:      0
     speed: 0 Mbps now, 0 Mbps max
OFPT_GET_CONFIG_REPLY (OF1.3) (xid=0x5): frags=normal miss_send_len=0

Open vSwitch-1

Create a Group table on Open vSwitch-1. Forward packets to port e3, e4, and e5 by select algorithm(round robin). Insert a flow from e2 forward to group 5566 and add another flows in order to recieve packets.

sudo ovs-ofctl -O OpenFlow13 add-group brLAN group_id=5566,type=select,bucket=output:8,bucket=output:6,bucket=output:5
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN in_port=102,actions=group:5566
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.1,actions=output:102
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.1,actions=output:102
sudo ovs-ofctl -O OpenFlow13 dump-flows brLAN
OFPST_FLOW reply (OF1.3) (xid=0x2):
 cookie=0x0, duration=0.011s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.1 actions=output:102
 cookie=0x0, duration=0.005s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.1 actions=output:102
 cookie=0x0, duration=0.017s, table=0, n_packets=0, n_bytes=0, in_port=102 actions=group:5566

Open vSwitch-2, 3, and 4

Insert flows to forward packets form/to Open vSwitch-1. (eth2 <-> eth3)

sudo ovs-ofctl -O OpenFlow13 add-flow brLAN in_port=102,actions=output:103
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN in_port=103,actions=output:102
sudo ovs-ofctl -O OpenFlow13 dump-flows brLAN
OFPST_FLOW reply (OF1.3) (xid=0x2):
 cookie=0x0, duration=0.010s, table=0, n_packets=0, n_bytes=0, in_port=102 actions=output:103
 cookie=0x0, duration=0.005s, table=0, n_packets=0, n_bytes=0, in_port=103 actions=output:102

Open vSwitch-5

Forward packets by IP address.

sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.2,actions=output:105
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.2,actions=output:105       
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.3,actions=output:106
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.3,actions=output:106       
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.4,actions=output:107
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.4,actions=output:107       
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.5,actions=output:108
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.5,actions=output:108       
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.6,actions=output:109
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.6,actions=output:109       
sudo ovs-ofctl -O OpenFlow13 dump-flows brLAN
OFPST_FLOW reply (OF1.3) (xid=0x2):
 cookie=0x0, duration=0.026s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.4 actions=output:107
 cookie=0x0, duration=0.015s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.5 actions=output:108
 cookie=0x0, duration=0.021s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.5 actions=output:108
 cookie=0x0, duration=0.010s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.6 actions=output:109
 cookie=0x0, duration=0.052s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.2 actions=output:105
 cookie=0x0, duration=0.041s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.3 actions=output:106
 cookie=0x0, duration=0.005s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.6 actions=output:109
 cookie=0x0, duration=0.047s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.2 actions=output:105
 cookie=0x0, duration=0.036s, table=0, n_packets=0, n_bytes=0, arp,arp_tpa=192.168.0.3 actions=output:106
 cookie=0x0, duration=0.031s, table=0, n_packets=0, n_bytes=0, ip,nw_dst=192.168.0.4 actions=output:107

Packect to Host-1

sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0800,ip_dst=192.168.0.1,actions=output:102
sudo ovs-ofctl -O OpenFlow13 add-flow brLAN eth_type=0x0806,ip_dst=192.168.0.1,actions=output:102

References

Chi-She ng Su