82 Software Networks
only allows for 4096 VLANs, because of the 12 bits in that zone. This
category of protocols includes:
– VXLAN (Ethernet in UDP), originally developed by VMware;
– NVGRE (Ethernet in IP), developed by Microsoft;
– 11aq (EVLAN), stemming from the standardization of CarrierGrade Ethernet.
At the very least, the following two protocols need to be added to
this list:
– MPLS, developed by operators and standardized by the ITU and
the IETF,
– LISP (IP in IP) supported by numerous hardware manufacturers.
The last of these protocols – LISP (Locator/Identifier Separation
Protocol) – is fundamentally different from the previous ones, because
it is a level-3 protocol, which is the encapsulation of an IP packet
within an IP packet. The reason for this encapsulation is the need to
have two IP addresses associated with an end device: the inner address
to identify the intended receiver and the outer address for routing. This
latter address denotes the physical position of the receiver. This
solution means that the virtual machines can be moved but retain the
same identity by modifying the IP address of the placement of the
virtual machine. We shall also come back to this in greater detail later
on.
Finally, the rising protocol corresponds to that developed for SDN:
it is OpenFlow, which was introduced by Nicira, later acquired by
VMware. We shall begin with a look at this protocol.
Remember that, as illustrated by Figure 4.1, SDN (SoftwareDefined Networking) is the solution which decouples the data plane
from the control plane. The computations and control algorithms no
longer take place directly in the nodes of the network, routers or
switches, but in a server situated somewhere in the network, called the
controller. The controller may be a physical device or a virtual
machine situated in a datacenter of greater or lesser size.
www.it-ebooks.info
only allows for 4096 VLANs, because of the 12 bits in that zone. This
category of protocols includes:
– VXLAN (Ethernet in UDP), originally developed by VMware;
– NVGRE (Ethernet in IP), developed by Microsoft;
– 11aq (EVLAN), stemming from the standardization of CarrierGrade Ethernet.
At the very least, the following two protocols need to be added to
this list:
– MPLS, developed by operators and standardized by the ITU and
the IETF,
– LISP (IP in IP) supported by numerous hardware manufacturers.
The last of these protocols – LISP (Locator/Identifier Separation
Protocol) – is fundamentally different from the previous ones, because
it is a level-3 protocol, which is the encapsulation of an IP packet
within an IP packet. The reason for this encapsulation is the need to
have two IP addresses associated with an end device: the inner address
to identify the intended receiver and the outer address for routing. This
latter address denotes the physical position of the receiver. This
solution means that the virtual machines can be moved but retain the
same identity by modifying the IP address of the placement of the
virtual machine. We shall also come back to this in greater detail later
on.
Finally, the rising protocol corresponds to that developed for SDN:
it is OpenFlow, which was introduced by Nicira, later acquired by
VMware. We shall begin with a look at this protocol.
Remember that, as illustrated by Figure 4.1, SDN (SoftwareDefined Networking) is the solution which decouples the data plane
from the control plane. The computations and control algorithms no
longer take place directly in the nodes of the network, routers or
switches, but in a server situated somewhere in the network, called the
controller. The controller may be a physical device or a virtual
machine situated in a datacenter of greater or lesser size.
www.it-ebooks.info