basic use of mininet, wireshark for studying OvS

1. Mininet, Wireshark and
Open vSwitch
a study notes
Richard Kuo, Professional-Technical Architect,
Domain 2.0 Architecture & Planning

2. Motivation
• Understand some basic network engineering tools
for SDN/NFV and network virtualization, which can
be served as building blocks for knowledge
development.
4/10/15 Creatie Common, SA, NC 2

3. Network Virtualization
• User Interface
• Network Services
• Controller
• Logic Network
• Virtualization
• Physical Network Resources
• Software operating environment
(VM, container)
• Analytics, Policy, Goal, QoS, SLA
• OSS and BSS
• Service composition, chaining
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4. Mininet
• http://mininet.org/
• Mininet is a network emulator, it
creates a virtual network, runs on
VM, cloud or native machine:
•
OpenVirtex, FlowVisor
ODL, ONOS,…
Mininet, OvS,
Wireshark, …
VPN, LB, DPI,..
OpenFlow
(Southbound)
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5. Mininet
$ sudo mn --topo single,3 --mac --
switch ovsk --controller=remote
$ sudo mn --topo linear,4 --mac --
switch ovsk --controller=remote
$ sudo mn --topo tree,3 --mac --switch
ovsk --controller=remote
from: NDI Communication
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6. Mininet Commands
• Default topology (h1, h2, s1, c0)
• sudo mn
• nodes
• net
• dump
• pingall
• h1 ping h2 –c3
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7. Wireshark
• supports hundreds of
protocolshttp://www.wireshark.or
g/docs/dfref/
• Live capture and offline analysis
• Multiplatform: Windows, Linux,
MAC
• Captured data browsing in GUI or
in TTY mode (TSHARK)
• R/W many different capture file
formats: tcpdump (libpcap), MS
Network Monitor, Network
General Sniffer®, RADCOM
WAN/LAN Analyzer and many
others.
• Output can be exported to XML,
PostScript® or simple text
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8. Wireshark
• Packet list
• Packet details
• Packet bytes
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9. Open vSwitch
• A software-based solution
• An implementation of
OpenFlow
• Flexible Controller in user-
space and fast datapath in
Kernel
• Flow Decision
• Decision about how to process
packet made in user-space
• First packet of new flow goes to
ovs-vswitchd, following packets
hit cached entry in kernel
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10. Features
• Visibility into inter-VM communication via NetFlow,
sFlow(R), IPFIX, SPAN, RSPAN, and GRE-tunneled
mirrors
• Support features on a Linux system:
– Fully functional Layer 2 switch
– NetFlow, sFlow, SPAN, and RSPAN support
– 802.1Q VLANs with trunking
– QoS
– Port aggregation
– GRE tunneling
– Compatibility with the Linux bridge code (brctl)
– Kernel and userspace switch implementation
• Fine-grained QoS control
• Support for HFSC qdisc
• Per VM interface traffic policing
• NIC bonding with source-MAC load balancing,
active backup, and L4 hashing
• OpenFlow protocol support (including many
extensions for virtualization)
• IPv6 support
• Multiple tunneling protocols
– GRE, VXLAN, IPsec, GRE and VXLAN over IPsec
• Remote configuration protocol with C and Python
bindings
• Kernel and user-space forwarding engine options
• Multi-table forwarding pipeline with flow-caching
engine
• Forwarding layer abstraction to ease porting to new
software and hardware platforms
• Feature list for container is in process
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11. Open vSwitch Schema
• Database that holds switch level
configuration
• Custom database with nice
properties:
• Log-based
• Speaks OVSDB management
protocol(JSON-RPC) to manager
and ovs-vswitchd
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12. Hardware VTEP Schema
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13. OvS Core Components
• ovs-vswitchd
• ovs-kernel
• ovsdb, ovsdb-server
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14. The example of QoS in OVS Database
• It is a GUI tool to see the tables in the ovsdb-server
• This case is about checking QoS setting

15. ovs-appctl
ovs-appctl is a utility for managing
these daemons at runtime. It is
useful for configuring log module
settings as well as viewing all
OpenFlow flows, including hidden
ones.
4/10/15 Creatie Common, SA, NC 15

16. ovs-dpctl
ovs-dpctl is very similar to ovs-
ofctl in that they both show flow
table entries. The flows that ovs-
dpctl prints are always an exact
match and reflect packets that
have actually passed through the
system within the last few
seconds.
.
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17. ovs-ofctl
This tool is used for administering
and monitoring OpenFlow
switches. Even if OVS isn't
configured for centralized
administration, ovs-ofctl can be
used to show the current state of
OVS including features,
configuration, and table entries.
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18. ovs-vsctl
This tool is used for configuration
and viewing OVS switch
operations:
• Port configuration,
• bridge additions/deletions,
• bonding,
• VLAN tagging
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19. Demo
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