I don't get SDNs. What problem are they solving? Aren't networks already defined by software?
>>55350722
> What problems are they solving?
Maintenance
> Aren't networks already defined by software?
I don't know what you mean by this?
Do you mean the software running on the routers/switches/hubs or the network stack?
>>55350722
I'm curious about this too. When I first heard about SDNs, I was like how the fuck does that even work
>>55350940
It's basically high level management software that lets you do remote configuration.
Instead of going to each box individually and changing the settings you can do it from your office.
>>55350959
lets take away even more jobs from the goy
It also adds the benefit of abstracting lower-level bullshit away from core network staff. Consider containers and microservices with microsegmentation. You have a tiny capsule of work with, in more traditional networking scenarios a shit ton of human overhead.
>>55350722
>Aren't networks already defined by software?
Sort of. Routers are really powerful, but they're generally "stupid" and locked into whatever they were built for.
What if you run an Ethernet network and one day you decide you need more control over how packets are routed through your network? You could make a bunch of crazy routing and firewall rules, but that's a pain and it may not even cover what you want. SDNs basically let you build a network however you want, with routers just being generalized... routers. With SDNs, you could build multiple networks that use the same network hardware. Sort of like VLANs, but with way more flexibility.
http://archive.openflow.org/documents/openflow-wp-latest.pdf
>>55350978
let's make repetitive task repetitive for the sake of tradition
>>55350899
I mean you can already control the route tables, blacklists, and literally every setting a router has from either SSH or SNMP, at least in enterprise stuff from 10 years ago. And products were always offering ways of aggregating control to routers and switches. I have to assume SDN is something more than that. Maybe its specifically tying container lifetimes to network routing? But you could already do that with DHCP, ARP, DNS, all the network maintenance protocols already work towards some management service controlling their behavior.
>>55350959
What's a high level action you can do with an SDN?
>>55351121
What more control do they offer? Ethernet doesn't even deal in packets but datagrams, its up to layer 2 to define packets, and if you want segregation of traffic with identical IPs you have VLAN optional headers to work with. So the only reason is if you had virtual vlans... which is just kind of... why?
Over time the hardware you use becomes very fast and capable. Eventually it becomes capable of emulating in software what once required dedicated hardware. It happens with most things. Virtual machines and cloud hardware resource pools were just the beginning.
>>55350722
NSX and Cisco ACI allow centralized low layer steering of traffic to virtual and/or non-virtual hosts. NSX's distributed virtual switch currently suffers from some performance bottlenecks for a high traffic datacenter, but the 9k (hardware/software mix) is very fast (although looking at 500k+ usd). They are both different takes on SDN. NVFs are what you should really be asking about.
>>55350722
Why the fuck would you make a thread about this outside the /sqt/ when you couldn't even be bothered enough to read the Wikipedia page about it?
