Introduction to SDN (Software Defined Networking)

Lessons Discussion
21

Hello Surendra

In the following documentation, you will find the recommended configuration procedure for Bridge Domains. In it, you will find several application scenarios and the resulting settings for ARP flooding and other parameters as well.

This document also includes a detailed explanation of what the ARP flooding parameter does and how it actually works. This should give a well-rounded view of what should be done in most cases.

I hope this has been helpful!

Laz

22

thank you lagapides i will check further

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23

merci infiniment M Rene ce cours a Ă©tĂ© trĂšs bien expliquĂ© ça m’a permit de comprendre le dĂ©but du cours d’automatisation alors que j’avais laissĂ© ce module parce que je ne comprenais absolument rien

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24

Hi,

I’d like to ask about this passage:
"With SDN, we use a central controller for the control plane. Depending on the vendor’s SDN solution, this could mean that the SDN controller takes over the control plane 100% or that it only has insight in the control plane of all network devices in the network. "

So there are no routing and MAC address tables on the networking devices? If that’s the case, then do the routers and switches have to query the SDN every single time a packet or frame has to be forwarded? How do they know how to locate the SDN if all of their local tables are empty? Or isn’t it the case that there are still local routing and MAC address (and ARP) tables on the devices, but their entries aren’t populated by the given device, but by the SDN?

Thanks.
Attila

25

Hello Attila

Network devices still maintain MAC address tables as well as routing tables to fulfil their functionality. When we say that there is a “central controller for the control plane” it doesn’t mean that the central controller performs all of the control plane functions. Conversely, it centralizes the management of the control plane.

So you don’t have to go into every router to configure OSPF or BGP, and you don’t have to go into every switch to configure port security, or you don’t have to go into every firewall and apply security policies. All of these are configured at the controller, and the controller will then instruct all of the network devices on how to modify their configurations to fulfil the requirements.

Practically, this means that you as a network administrator will be able to manage the network (composed of dozens of switches, routers, firewalls, access points etc
) from a single control panel rather than needing to go into every device separately to modify its operation. Does that make sense?

I hope this has been helpful!

Laz

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