Hi All,
Blogging after a very very long time again!!
This time decided to blog on OpenStack and believe me this is
the toughest topic of all in the openstack architecture to understand.
PROJECT NEUTRON - Openstack Project that deals with
networking services in a cloud environment.
When we try to find the how networking components
of Openstack internally works, google is full of pictures all over, beautiful pictures but
understanding it will be quite a challenge. So, decided to blog on it and take it step by step to understand the networking behind the scenes and how virtual machines gets connected to outside world.
We will be following the below sequence to understand the
concept in detail.
§ Physical wiring of ethernet using 2 ethernet interfaces
o (2 cables, we will create a bonding)
§ Ethernet bonding
o (Doubles the speed, and increased reliability, active-active)
§ Ethernet tagging
o (Thats why we need only 2 interfaces)
§ Network function virtualization (NFV)
o Openstack will not
help you, you have to put this in place by yourself.
§ Tie all the above together in a single and final picture
Advantages of Bonding
========================
-Spec: 802.3ad
-Active-active mechanism
-Aggregate traffic balances on both cables
-Individual flows do NOT balance
-If any connection fails, traffic moves the connection that
is active
(100 Ms failover time)
How to do ethernet bonding?
===========================
Network config file /etc/network.interfaces
(Debian system, if non-debian system make necessary changes)
auto bond0
iface bond0 inet manual
bond-mode 802.3ad
bond-miimon 200
bond-slaves none
up ip link set dev $IFACE up
down ip link set dev $IFACE down
#Bond Slave
auto
etho_interface.stdout
iface eth0_interface.stdout inet manual
bond-master bond0
bond-primary eth0_interface.stdout
#Bond Slave
auto
eth1_interface.stdout
iface eth1_interface.stdout inet manual
bond-master bond0
How to setup the VLAN trunk for management & provider
network?
===============================================================
Network config file /etc/network.interfaces
(Debian system, if non-debian system make necessary changes)
#Management VLAN
auto bond0.1600
iface bond0.1600 inet manual
up ip link set dev $IFACE up
down ip link set dev $IFACE down
#Provider VLAN
auto bond0.1200
iface bond0.1200 inet manual
up ip link set dev $IFACE up
down ip link set dev $IFACE down
Network Function virtualization (NFV)
======================================
1) Create the management bridge
sudo ovs-vsctl add-br
br-mgmt
2) Attach the VLAN 1600 interface to management bridge
sudo ovs-vsctl add-port
br-mgmt bond0.1600
3) Create the provider bridge
sudo ovs-vsctl add-br
br-ex
4) Attach the VLAN 1200 interface to management bridge
sudo ovs-vsctl add-port
br-ex bond0.1200
5) Create the VLAN bridge
sudo ovs-vsctl add-br
br-vlan
6) Attach all VLAN (trunk) to the VLAN brodge
sudo ovs-vsctl add-port
br-vlan bond0
Eight Network Function Virtualization Components
====================================
1) Tap interface
- One end to VM referred as Virtual NIC
- Other end into (5) or (6) or (7) or (8)
2) veth
- One end Openstack Controller, Network, Block or Object
Storage nodes
- Other end into (6) or (7) or (8). cannot be plugged into
Virtual Machine
3) Bridge internal (OVS Only)
4) Patch (OVS Only)
5) IP Tables
6) Linux Network Stack (Namespace "ip netns")
- If we put IPTables inside of namespace, we configure
IpTables we can make namespace
perform as a router/NAT/LoadBalancer etc.
7) OVS (OpenvSwitch)
8) Linux Bridge
Namespace create a isolated virtual linux network stack (It
may include dnsmasq, virtual router, private networks & subnets etc…)
Note:-
We may use OVS or Linux Bridge (Actually both are
competitors)
Linux Bridge Vs Open vSwitch
========================================
HAPPY LEARNING!
