Introduzione a Software Define Networking
-
Upload
festival-ict-2014 -
Category
Technology
-
view
371 -
download
0
Transcript of Introduzione a Software Define Networking
1
Customer Driven Innovation
1
Do not distribute/edit/copy without the written consent of A10 Networks
SDN: an Introduction Luca Profico [email protected]
2
Who am I
� Luca Profico
� RSE@a10networks
� A10 Networks ¿ Networking company based in San Jose (CA) ¿ 10 years developing its own solutions ¿ 3# worldwide marketshare in ADC Market; #1 in Japan ¿ Leader in CGN and IPv6 Migration solutions
3
Software-defined Networking
• SDN concept has been around for almost 9 years now but the concept is not yet clear
• Marketing is riding SDN with bigger and bigger promises
• What will we do with SDN?
• US ICT Event survey: • SDN, I don’t understand it but I want it. • All this fuss for old concepts remixed. • Will I lose my job because of SDN?
4
What is, What is Not
� SDN is not a protocol
� SDN is not a suite of protocols
� SDN is not a technology
� SDN is a concept, a methodology, an architecture that aims at making network implementation, scalability and management easier by separating planes
5
Network Devices and Planes
Build and exchange informa2on
ARP MAC Learning STP …
Rou2ng protocols Neighbors …
Build and store local L2/L3 info tables
Packet processing/forwarding decisions
Forwarding table
Control plane
Data plane
fwd tbl
p1
p3
p2
6
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Network Devices and Planes
7
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Network Devices and Planes
8
Data plane
fwd tbl
Data plane
fwd tbl
Data plane
fwd tbl
Data plane
fwd tbl
Control plane
Data plane
fwd tbl
Data
plane vendor B
fwd tbl
Data
plane vendor C
fwd tbl
Network Devices and Planes
9
Network
Network operating system
Middleware
vSwitch Switch Switch Switch Switch vSwitch vSwitch
SDN Controller
Network Applica2on
Network Applica2on
Network Applica2on
Network Applica2on
Northbound API
Southbound API
SDN Implementation
10
Open Networking Foundation
� Members-only organization
� Milestones ¿ Founded in 2011 ¿ More than 50 members in 1st yr. ¿ Over 100 members in 2013 (Vendors, SPs, Telcos)
11
OpenFlow
� Standard communication interface between control and forwarding layer
� OpenFlow specs ¿ OF Switch specs 1.3.2 published 2013 ¿ OF Switch specs 1.4 approved 2013 ¿ OF-Config (conf & mgmt protocol) 1.1.1 published 2013
� Simple traffic processing ¿ Flow tables ¿ Pipeline concept ¿ OpenFlow Switches ¿ Hybrid OpenFlow Switches
12
OpenFlow Tables
Flow Table Group Table Meter Table
Match fields Priority Counters Instructions Timeout Cookie
Group Identifier Group Type Counters Action Buckets
Meter Identifier Meter Bands Counters
MAC src MAC dst IP src IP dst TCP dport … Action Count
* 10:20:. * * * * Port 1 99
* * 217.99.* * * * Table 6 18
* .:38:aa:. * * * * drop 4
* * * 7.7.9.4 25 * drop 172
* * * * 69 * local 19
* * * * * * controller 2993
13
switch
Example: Life of a Packet
Flow Table
Group Table
Group Table
Meter Table
Next table
Action 1 Action 2 Action 3 Next table
Action 4 Next table
Action 5 Output
Action set
14
OpenFlow Challenges
� Protocol status. OF is simple. Maybe *too* simple
� Which functionalities should stay resident?
� Large networks flow programming
� Hi-rate flow table update
� Vendors proprietary protocols
15
Overlays
� VLAN on traditional networks has limitations ¿ Number of instances ¿ Transport ¿ Overlapping
� Some solutions have been tried ¿ HVLAN, QinQ, PBT, PBB-TE, Mac-in-mac, …
� With SDN we talk about Overlay networks ¿ Used to create virtual network containers logically isolated from the
others, while sharing the underlying physical network ¿ Always based on encapsulation. Usually tunnels are terminated on
softswitch
16
VXLAN
� Virtual Extensible LAN ¿ Broadest industry support
� VXLAN ¿ Layer 2 frames in UDP packets ¿ VLAN frames are preserved – multiple Layer 3 networks inside a VXLAN
segment ¿ Uses multicast to transport broadcasts (openflow may avoid that) ¿ Tenants see their own “normal” network ¿ Underlying network sees UDP VXLAN traffic with a segment ID ¿ VXLAN ID is 24 bits = 16 Million tenants sharing the same infrastructure
17
50 Bytes More. Jumbo Frames!
14 bytes Outer MAC Header
20 bytes Outer IP Header
8 bytes Outer UDP Header
8 bytes VXLAN Header
Original L2 frame (VLAN tag included)
18
Multi-tenant SDN Network
Switch Switch Switch Switch Switch Switch Switch Switch
Server Server Server Server Server Server
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSwitch vSwitch vSwitch vSwitch vSwitch vSwitch
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
vSer
ver
SDN Controller
Network Apps/UI/…
19
NVGRE, STT, NVO3
� NVGRE ¿ Similar to VXLAN ¿ Microsoft pushes it ¿ Overlay of choice in Hyper-V ¿ Does not require multicast to carry broadcast, unknown unicast, multicast
° Hyper-V embedded switch (Windows Network Virtualization Module) is pre-populated with all host-to-tunnel mappings by powershell CMDlets
° No flooding, as there is no unknown node
� STT ¿ Stateless Transport Tunneling ¿ Encapsulation leverages some specific network card capabilities, like
TSO (TCP segmentation offload) ¿ Nicira developed it. Nicira has been acquired by VMware
� NVO3 ¿ Network Virtualization Overlays 3 - Developed by a group in IETF
20
SDN Actual Use Cases
� Link usage optimization
� Distributed packet filtering
� NAC for devices that do not support 802.1x
� Service insertion, service chaining
� Network traffic analysis, TAP aggregation
� Basic link/service load balancing
21
SDN Challenges
� Southbound API is uncertain and will be fragmented
� Scalability issues ¿ Number of flows
� Performance issues ¿ Rate of flow-table updates
� Redundancy
� Vendors’ SDN controllers (OpenDaylight project?)
� Know-how
� Security
22
Conclusions
� SDN future is uncertain, at the moment most of the development is being done on large data centers, backbones, virtualization spaces
� So far there is no real use for the enterprise
� The southbound API will most probably be fragmented
� It will take some time: as some analysts point out, it took server virtualization 10 years to become mainstream, while openflow 1° release was born in 2009
� SDN will add up to $400M within the networking market in 2014 (Doyle Research)
� In the end, the market will decide what SDN will be, where it will be used, what applications we’ll write on it
23 23 Do not distribute/edit/copy without the written consent of A10 Networks
Thank You
www.a10networks.com