OpenNebula

Why VXLAN (Virtual eXtensible Local Area Network)?

Why (routed) multicast?

• VXLAN needs multicast in physical network if there's no network controller
• Routed multicast allows for easier scaling between datacenters based on L3

How it works with OpenNebula

• Makes use of VXLAN support in linux kernel (>= 3.7)
• A 1:1 mapping of VXLAN network to a multicast group (i.e vxlan 1 maps to 239.0.0.1)

ONE VXLAN driver code

OpenNebula.exec_and_log("#{command(:ip)} link \
add #{@nic[:vlan_dev]}" " #{mtu} type vxlan id #{@nic[:vlan_id]} \
group #{mcs} ttl 10" " dev #{@nic[:phydev]}")

sudo brctl addbr vxlan50
sudo ip link set vxlan50 up
sudo ip link add vlan601.50 mtu 1500 type vxlan id 50 \
group 239.0.0.50 ttl 10 dev vlan601
sudo ip link set vlan601.50 up
sudo brctl addif vxlan50 vlan601.50

<interface type='bridge'>
<source bridge='vxlan50'/>
<mac address='02:02:c0:a8:4d:01'/>
<model type='virtio'/>
</interface>

vxlan50:  mtu 1500 \
qdisc noqueue state UP group default 
    link/ether 5e:c5:a9:7f:53:74 brd ff:ff:ff:ff:ff:ff
vlan601.50:  mtu 1500 \
qdisc noqueue master vxlan50 state UNKNOWN group default 
    link/ether 5e:c5:a9:7f:53:74 brd ff:ff:ff:ff:ff:ff
vnet7:  mtu 1500 \
qdisc pfifo_fast master vxlan50 state UNKNOWN group default qlen 500
    link/ether fe:02:c0:a8:4d:02 brd ff:ff:ff:ff:ff:ff

Juniper x4300 switch config

interfaces {
    irb {
        unit 601 {
            family inet {
                address 10.60.1.1/24;
            }
        }
        unit 701 {
            family inet {
                address 10.70.1.1/24;
            }
        }
        unit 801 {
            family inet {
                address 10.80.1.1/24;
            }
        }
    }
    lo0 {
        unit 0 {
            family inet {
                address 172.17.1.1/32 {
                }
            }
        }
    }
}
routing-options {
    router-id 172.17.1.1;
}
protocols {
    igmp {
        interface irb.601 {
            version 3;
            immediate-leave;
        }
        interface irb.701 {
            version 3;
            immediate-leave;
        }
        interface irb.801 {
            version 3;
            immediate-leave;
        }
        interface lo0.0 {
            version 3;
            immediate-leave;
        }
    }
    pim {
        rp {
            local {
                family inet {
                    address 172.17.1.1;
                }
            }
        }
        interface lo0.0 {
            mode sparse;
            version 2;
        }
        interface irb.601 {
            mode sparse;
            version 2;
        }
        interface irb.701 {
            mode sparse;
            version 2;
        }
        interface irb.801 {
            mode sparse;
            version 2;
        }
    }
}
vlans {
    hv_rack1 {
        vlan-id 601;
        l3-interface irb.601;
    }
    hv_rack2 {
        vlan-id 701;
        l3-interface irb.701;
    }
    hv_rack3 {
        vlan-id 801;
        l3-interface irb.801;
    }
}
                    

Administratively Scoped IPv4 Multicast addresses (RFC 2365)

sipcalc 239.0.0.0/8
-[ipv4 : 239.0.0.0/8] - 0

[CIDR]
Host address            - 239.0.0.0
Host address (decimal)  - 4009754624
Host address (hex)      - EF000000
Network address         - 239.0.0.0
Network mask            - 255.0.0.0
Network mask (bits)     - 8
Network mask (hex)      - FF000000
Broadcast address       - 239.255.255.255
Cisco wildcard          - 0.255.255.255
Addresses in network    - 16777216
Network range           - 239.0.0.0 - 239.255.255.255
Usable range            - 239.0.0.1 - 239.255.255.254

MTU