I recently started working with SDN and floodlight controller. I want to changing routing algorithme in floodlight by deleting the algorithm exist (Dijkstra algorithm), any link for that ?
Floodlight controller has a topology manager that takes care of maintaining the
network graph, functionalities for finding routes through the topology via algorithm for the controller. Dijakstra runs in topology manager. You may need to update the Topology manager and its related dependencies as per your requirement.
The below link could be one good starting point
https://github.com/floodlight/floodlight/blob/master/src/main/java/net/floodlightcontroller/topology/TopologyManager.java
Based on Dijskstra, the Yen's algorithm shall form shortest path, in the order of shortest path which shall get stored in pathCache for usage. The Topology manager interacts and helps in exposing the path information.
Application modules like Forwarding module shall retrieve the path from Topology Manager and then insert flows over the path based on learned source, destination.
Controller module like TopologyService help in maintaining the topology related information for the controller, as well as to find routing in the network.
You may need to update the modules as per your algorithm with few additional details https://floodlight.atlassian.net/wiki/spaces/floodlightcontroller/pages/1343513/How+to+Write+a+Module
Related
I'm new to CF workers and the wrangler publish system, and I can find very little information around my requirements within online sources, perhaps my search query is wrong, so hoping I can find some help here.
I have an NX workspace, containing 2x apps. One app is deployed into the top-level worker, and the second one should be deployed to a sub-directory in the same worker, effectively create a parent-child structure, like the following:
example.com/ -> top-level app
example.com/site2/ -> child-level app
My issue is, I do not understand where and how to define, in wrangler.toml, the /sub-directory/. Should I have 2x separate worker-sites for these? I was under the impression that, I could just update the worker (index.js) file in my single worker-site to handle /site2/ otherwise treat the request as standard?
All I would really like to know is, how can I specify that my publish should to the /site2/ sub-directory, if at all possible?
Thanks in advance.
There are a couple ways to handle this. If your code / logic in the workers for the top-level vs child-level is completely different, I'd recommend using two separate workers. Then you can configure which "routes" each worker will run on -
https://developers.cloudflare.com/workers/cli-wrangler/configuration
Worker 1 could be -
routes = ["example.com/"]
Worker 2 could be -
routes = ["example.com/site2/"]
Check this out for more details on how routing / matching behaves -
https://developers.cloudflare.com/workers/platform/routes#matching-behavior
The other way to do it would be to have a single worker, and inspect the incoming request to behave differently depending on whether the request is at the root, or at /site2/. I'd only recommend this if there are small differences between how the two sites should behave (e.g. swapping out a variable).
I am using Oendaylight (carbon) to develop an SDN application consisting of multiple switches that connect to a controller. I want to be able to deploy different applications on different switches when they connect. How can I specify this? For example when openflow:1 connects, I want to deploy an L2 switch on it and when openflow:2 connects, I want to deploy a different application on it. Thanks.
First of all, you do not deploy applications on switches. Applications run on controller, you can add a logic which programs selected switches only.
What you essentially want to do is reactive programming; wait for events and act accordingly. This can be easily achieved by hooking the event listeners to the nodes in YANG model of the application. Any change in these nodes will be then notified to your application which can then do selective network programming.
In the example mentioned, you will need to use "InstanceIdentifier" object to identify which data model's events you are interested in listening.
InstanceIdentifier<Node> nodeID = InstanceIdentifier.builder(Nodes.class).child(Node.class, new NodeKey(node.getId())) .augmentation(FlowCapableNode.class)
.build();
Now simply register a listener to this IID by using DataBroker object's registerDataChangeListener method.
db.registerDataChangeListener(LogicalDatastoreType.CONFIGURATION, nodeID, this, AsyncDataBroker.DataChangeScope.SUBTREE);
At this point in time, you will be notified of any update (addition/modifification/deletion) of the switches you have registered for.
Finally to catch the event use/override DataChangeListener interface's onDataChanged method and add your fancy logic.
The similar logic can be fine grained to listen to activities on particular flow tables, flow rules, etc on the switch.
I have to create a particular simulation for a college project. The simulation should feature several mobile nodes cyclically switch between 802.11 access point and station modes. While in station mode, nodes should read the SSIDs of access points around them, and then they should change their SSID in AP mode accordingly. There is no need for connections or data exchange between the nodes beside the SSID reading.
Now, I've been through Omnet/Inet tutorials/documentation (all two of them), and I feel pretty much stuck.
What I could use right now is someone confirming my understanding of the framework giving me some directions on how exactly I should proceed.
From what I understand is Inet does not implement any direct/easy way to do what I'm trying to do. Most examples have fixed connections declared in NED files and hosts with a fixed status (AP or STA) defined in the .ini file.
So my question is basically how do I do that: do I need to extend a module (say, wirelessHost), modifying its runtime behaviour, or should I implement a new application (like UDPApp) to have my node read other SSIDs and change his accordingly? And what is the best way to access an host's SSID?
You may utilize two radios for each mobile node e.g. **.mobilenode[*].numRadios = 2 (see also example in /inet/examples/wireless/multiradio/).
The first radio operates as AP **.mobilenode[*].wlan[0].mgmtType = "Ieee80211MgmtAPSimplified" which has to adapt its SSID.
The second radio serves as STA **.mobilenode[*].wlan[1].mgmtType = "Ieee80211MgmtSTA". Now, you have to sub-class Ieee80211AgentSTA which handles the SSID scanning procedure and has to change the first radio's SSID upon new SSID detection. Then you utilize the adopted sub-class within the simulation. Finally, active scanning has to be activated **.mobilenode[*].wlan[1].agent.activeScan = true.
I am creating a simple network with mininet. and i want block traffic from one host to another with controller.I Want know which of RYU API useful for me.parser."OFPMatch" or another RYU API
Something you may find useful for working with the Ryu controller is Ryuretic. It provides an additional layer of abstraction for the Ryu Controller, so all you have to worry with is the incoming packet.
The Ryuretic backend renders all events to the user as a pkt (a dictionary object), and the contents of the pkt are retrieved by providing the header field of interest (e.g, pkt['srcmac'], pkt['dstmac'], pkt['ethtype'], pkt['inport'], pkt['srcip'], etc.) Using the information from the pkt, the user can choose which fields to match and what action (fwd, drop, redirect, mirror, craft) to take when a match is found.
To install Ryuretic, simply copy the [files] (https://github.com/Ryuretic/RyureticLabs/tree/master/ryu/ryu/app/Ryuretic) to the directory /ryu/ryu/app/Ryuretic. If you installed Ryu, then you already have the /ryu/ryu/app directory. You just need to create the Ryuretic directory and copy the files there.
Ryuretic Labs provides setup instruction and some use cases for implementing security features on SDNs using Ryuretic. It also provides a Mininet testbed for testing your network applications on the VM provided by SDN Hub.
Let me begin with an illustrative example (assume the implementation is in a statically typed language such as Java or C#).
Assume that you are building a content management system (CMS) or something similar. The data is hierarchically organised into Folders. Each folder has a collection of children; a child may be a Page or a Folder. All items are stored within a root folder. No cycles are allowed. We have an acyclic graph.
The system will have a remote API and instances of Folder and Page must be serialized / de-serialized across the network. With a typical implementation of folder, in which a folder's children are a List, serialization of the root node would send the entire graph. This is unacceptable for obvious reasons.
I am interested to hear people have solved this problem in the past.
I have two potential suggestions:
Navigation by query: Change the domain model so that the folder class contains only a list of IDs for each child. To access a child we must query for it. Serialisation is now trivial since the graph ends at a well defined point. The major downside is that we lose type safety - the ID could be for something other than a folder/child.
Stop and re-attach: During serialization stop whenever we detect a reference to a folder or page, send the ID instead. When de-serializing we must then look up the corresponding object for each ID and re-attach it at the relevant position in the nascent object.
I don't know what kind of API you are trying to build, but your suggestion #1 sounds like it is close to what is recommended for REST style services and APIs. Basically, a Folder object would contain a list of URLs to its children.
The Navigation by query solution was used for NFS. By reading through your question, it looks to me, as if you're trying to implements kind of a file system yourself.
If you're looking specifically into sending objects over the network there is always CORBA. Aside from that there is DCOM and the newer WCF. But wait there is more like RMI. Furthermore there are Web Services. I'll stop here now.
Suppose You model the whole tree with every element being a Node, specialisations of Node being Folder and, umm, Leaf. You have a "root" Node. Nodes have a methods
canHaveChildren()
getChildren()
Leaf nodes have the obvious behaviours (never even need to hit the network)
Folders getChildren() get the next set of nodes.
I did devise a system with Restful services along these lines. Seemed to be reasonably easy to program to.
I would not do it by the Navigation by query method. Simply because I would like to stick with the domain model where folders contains folders or pages.
Customizing the serialization might also be tricky, bug prone and difficult to change\understand.
I would suggest that you introduce and object like FolderBowser in your model which takes an id and gives you a list of contents of the folder. That will make your service operations simpler.
Cheers,
Unmesh
The classical solution is probably to use a proxy pattern, where some of the graph is sent over the network and some of the folders are replaced by proxies that will not have their lists of children populated until they are queried. A round trip to the server takes a significant amount of time and it will probably result in too many requests if all folders are proxies (this would yield a new request each time the contents of a folder is inspected), so you want to go for some trade off between the size of each chunk of data and the number of server requests needed in a typical scenario. This is of course application specific, but sending the contents of all child folders in for instance depth 2 might be a useful strategy...
Long story short: What will probably work best is your solution #1 with the exception that you want to send more than one folder at a time because of the overhead of a round trip to the server...