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InfluxDB and Grafana
The diagram shows the measurement pipeline. Standard sFlow measurements from hosts, hypervisors, virtual machines, containers, load balancers, web servers and network switches stream to the sFlow-RT real-time analytics engine. Over 40 vendors implement the sFlow standard and compatible products are listed on sFlow.org. The open source Host sFlow agent exports standard sFlow metrics from hosts. For additional background, the Velocity conference talk provides an introduction to sFlow and case study from a large social networking site.
It is possible to simply convert the raw sFlow metrics into InfluxDB metrics. The sflow2graphite.pl script provides an example that can be modified to support InfluxDB's native format, or used unmodified with the InfluxDB Graphite input plugin. However, there are scaleability advantages to placing the sFlow-RT analytics engine in front of the time series database. For example, in large scale cloud environments the metrics for each member of a dynamic pool isn't necessarily worth trending since virtual machines are frequently added and removed. Instead, sFlow-RT tracks all the Continue reading
Monitoring leaf and spine fabric performance
A leaf and spine fabric is challenging to monitor. The fabric spreads traffic across all the switches and links in order to maximize bandwidth. Unlike traditional hierarchical network designs, where a small number of links can be monitored to provide visibility, a leaf and spine network has no special links or switches where running CLI commands or attaching a probe would provide visibility. Even if it were possible to attach probes, the effective bandwidth of a leaf and spine network can be as high as a Petabit/second, well beyond the capabilities of current generation monitoring tools.
The 2 minute video provides an overview of some of the performance challenges with leaf and spine fabrics and demonstrates Fabric View - a monitoring solution that leverages industry standard sFlow instrumentation in commodity data center switches to provide real-time visibility into fabric performance. Fabric View is an application running on InMon's Switch Fabric Accelerator SDN controller. Other applications can automatically respond to problems and apply controls to protect against DDoS attacks, reduce latency and increase throughput.
Visit sFlow.com to learn more, evaluate pre-release versions of these products, or discuss requirements.
Open vSwitch 2014 Fall Conference
Open vSwitch is an open source software virtual switch that is popular in cloud environments such as OpenStack. Open vSwitch is a standard Linux component that forms the basis of a number of commercial and open source solutions for network virtualization, tenant isolation, and network function virtualization (NFV) - implementing distributed virtual firewalls and routers.
The recent Open vSwitch 2014 Fall Conference agenda included a wide variety speakers addressing a range of topics, including: large scale operation experiences at Rackspace, implementing stateful firewalls, Docker networking, and acceleration technologies (Intel DPDK and Netmap/VALE).
The video above is a recording of the following sFlow related talk from the conference:
Traffic visibility and control with sFlow (Peter Phaal, InMon)
sFlow instrumentation has been included in Open vSwitch since version 0.99.1 (released 25 Jan 2010). This talk will introduce the sFlow architecture and discuss how it differs from NetFlow/IPFIX, particularly in regards to delivering real-time flow analytics to an SDN controller. The talk will demonstrate that sFlow measurements from Open vSwitch are identical to sFlow measurements made in hardware on bare metal switches, providing unified, end-to-end, measurement across physical and virtual networks. Finally, Open vSwitch / Mininet will be used to demonstrate Continue reading
SDN fabric controllers
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| Credit: sFlow.com |
Despite differences, the advantages of a software based network edge are compelling and there is emerging consensus behind this architecture with a large number of solutions available, including: Hadoop, Mesos, OpenStack, VMware NSX, Juniper OpenContrail, Midokura Midonet, Nuage Networks Virtual Services Platform, CPLANE Dynamic Virtual Networks and PLUMgrid Open Networking Suite.
In addition, the move to a software based network edge is leading to the adoption of configuration management and deployment tools from the DevOps Continue reading
Super NORMAL
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| KennyK/Shutterstock |
HP's slide presentation from the design forum, OpenFlow-hybrid Mode, gives an overview of hybrid mode OpenFlow and its benefits. The advantage of hybrid mode in leveraging the proven scaleability and operational robustness of existing distributed control mechanisms and complementing them with centralized SDN control is compelling and a number of vendors have released support, including: Alcatel Lucent Enterprise, Brocade, Extreme, Hewlett-Packard, Mellanox, and Pica8. HP's presentation goes on to propose enhancements to the OpenDaylight controller to support hybrid OpenFlow agents.
InMon recently built a hybrid OpenFlow controller and, based on our experiences, this article will discuss how integrated hybrid mode is currently implemented on the switches, examine operational issues, and propose an agent profile for hybrid OpenFlow designed to reduce operational complexity, particularly when addressing traffic engineering use cases such as DDoS mitigation, large flow marking and large flow steering on ECMP/LAG networks.
Mechanisms for Optimizing LAG/ECMP Component Link Utilization in Networks is an IETF Continue reading
SDN control of hybrid packet / optical leaf and spine network
The short video above shows how the Calient optical circuit switch (OCS) uses two grids of micro-mirrors to create optical paths. The optical switching technology has a number of interesting properties:
- Pure optical cut-through, the speed of the link is limited only by the top of rack transceiver speeds (i.e. scales to 100G, 400G and beyond without having to upgrade the OCS)
- Ultra low latency - less than 50ns
- Lower cost than an equivalent packet switch
- Ultra low power (50W vs. 6KW for comparable packet switch)
The diagram shows the hybrid network that was demonstrated. The top of rack switches are bare metal switches running Cumulus Linux. The spine layer consists of a Cumulus Linux bare metal switch and a Calient Technologies optical circuit switch. The bare metal Continue reading
HP proposes hybrid OpenFlow discussion at Open Daylight design forum
Topics for ODL Design Summit from HP contains the following proposal, making the case for integrated hybrid OpenFlow:
We would like to share our experiences with Customer SDN deployments that require OpenFlow hybrid mode. Why it matters, implementation considerations, and how to achieve better support for it in ODL
OpenFlow-compliant switches come in two types: OpenFlow-only, and OpenFlow-hybrid. OpenFlow-only switches support only OpenFlow operation, in those switches all packets are processed by the OpenFlow pipeline, and cannot be processed otherwise. OpenFlow-hybrid switches support both OpenFlow operation and normal Ethernet switching operation, i.e. traditional L2 Ethernet switching, VLAN isolation, L3 routing (IPv4 routing, IPv6 routing...), ACL and QoS processing
The rationale for supporting hybrid mode is twofold:
- Controlled switches have decades of embedded traditional networking logic. The controller does not add value to a solution if it replicates traditional forwarding logic. One alternative controller responsibility is that provides forwarding decisions when it wants to override the traditional data-plane forwarding decision.
- Controllers can be gradually incorporated into a traditional network. Continue reading
DDoS mitigation with Cumulus Linux
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| Figure 1: Real-time SDN Analytics for DDoS mitigation |
This article builds on the test setup described in RESTful control of Cumulus Linux ACLs in order to implement the ONS 2014 SDN Idol winning distributed denial of service (DDoS) mitigation solution - Real-time SDN Analytics for DDoS mitigation.
The following sFlow-RT application implements basic DDoS mitigation functionality:
include('extras/json2.js');
// Define large flow as greater than 100Mbits/sec for 1 second or longer
var bytes_per_second = 100000000/8;
var duration_seconds = 1;
var id = 0;
var controls = {};
setFlow('udp_target',
{keys:'ipdestination,udpsourceport', value:'bytes',
filter:'direction=egress', t:duration_seconds}
);
setThreshold('attack',
{metric:'udp_target', value:bytes_per_second, byFlow:true, timeout:4,
filter:{ifspeed:[1000000000]}}
);
setEventHandler(function(evt) {
if(controls[evt.flowKey]) return;
var rulename = 'ddos' + id++;
var keys = evt.flowKey.split(',');
var acl = [
'[iptables]',
'# block UDP reflection attack',
'-A FORWARD --in-interface swp+ -d ' + keys[0]
+ ' -p udp --sport ' + keys[1] + ' -j DROP'
];
http('http://'+evt.agent+':8080/acl/'+rulename,
'put','application/json',JSON.stringify(acl));
controls[evt.flowKey] = {
agent:evt.agent,
dataSource:evt.dataSource,
rulename:rulename,
Continue reading
Docker performance monitoring
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| Visibility and the software defined data center |
The talk provides additional background on the sFlow standard and case studies. The remainder of this article describes how to use Host sFlow to monitor a Docker server pool.
First, download, compile and install the Host sFlow agent on a Docker host (Note: The agent needs to Continue reading
Microsoft Office 365 outage
6/24/2014 Information Week - Microsoft Exchange Online Suffers Service Outage, "Service disruptions with Microsoft's Exchange Online left many companies with no email on Tuesday."The following entry on the Microsoft 365 community forum describes the incident:
====================================The closure summary shows that operators took 8 hour 39 minutes to manually diagnose and remediate the problem with degraded networking infrastructure. The network related outage described in this example is not an isolated incident; other incidents described on this blog include: Packet loss, Amazon EC2 outage, Gmail outage, Delay vs utilization for Continue reading
Closure Summary: On Tuesday, June 24, 2014, at approximately 1:11 PM UTC, engineers received reports of an issue in which some customers were unable to access the Exchange Online service. Investigation determined that a portion of the networking infrastructure entered into a degraded state. Engineers made configuration changes on the affected capacity to remediate end-user impact. The issue was successfully fixed on Tuesday, June 24, 2014, at 9:50 PM UTC.
Customer Impact: Affected customers were unable to access the Exchange Online service.
Incident Start Time: Tuesday, June 24, 2014, at 1:11 PM UTC
Incident End Time: Tuesday, June 24, 2014, at 9:50 PM UTC
=====================================
RESTful control of Cumulus Linux ACLs
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| Figure 1: Elephants and Mice |
This article demonstrates a self contained real-time Elephant flow marking solution that leverages the visibility and control features of Cumulus Linux.
SDN fabric controller for commodity data center switches provides some background on the capabilities of the commodity switch hardware used to run Cumulus Linux. The article describes how the measurement and control capabilities of the hardware can be used to maximize data center fabric performance:
- Visibility: Cumulus recently added sFlow support, providing the network wide visibility needed for control - see Cumulus Networks, sFlow and data center automation.
- Control: Cumulus Linux Netfilter (ACLs) describes how standard Linux ebtables / iptables configuration files are used to manage the ACL/policy capabilities of the hardware.
For example, the following command creates a filter called Continue reading
Cumulus Networks, sFlow and data center automation
The Cumulus Linux platform makes it possible to run the same open source agent on switches, servers, and hypervisors - providing unified end-to-end visibility across the data center. The open networking model that Cumulus is pioneering offers exciting opportunities. Cumulus Linux allows popular open source server orchestration tools to also manage the network, and the combination of real-time, data center wide analytics with orchestration make it possible to create self-optimizing data centers.
Install and configure Host sFlow agent
The following command installs the Host sFlow agent on a Cumulus Linux switch:sudo apt-get install hsflowdNote: Network managers may find this command odd since it is usually not possible to install third party software on switch hardware. However, what is even more radical is that Cumulus Linux allows users to download source Continue reading
SDN fabric controller for commodity data center switches
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| Figure 1: Rise of merchant silicon |
This article will examine some of the factors leading to commoditization of network hardware and the role that software defined networking (SDN) plays in coordinating hardware resources to deliver increased network efficiency.
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| Figure 2: Fabric: A Retrospective on Evolving SDN |
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| Table 1: Edge vs Fabric Functionality |
Load balancing large flows on multi-path networks
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| Figure 1: Active control of large flows in a multi-path topology |
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| Figure 2: Two path topology |
To ensure that packets in a flow arrive in order at their destination, switch s3 computes a hash function over selected fields in the packets (e.g. source and destination IP addresses Continue reading
Mininet integrated hybrid OpenFlow testbed
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| Figure 1: Hybrid Programmable Forwarding Planes |
A number of vendors support sFlow and integrated hybrid OpenFlow today, examples described on this blog include: Alcatel-Lucent, Brocade, and Hewlett-Packard. However, building a physical testbed is expensive and time consuming. This article describes how to build an sFlow and hybrid OpenFlow testbed using free Mininet network emulation software. The testbed emulates ECMP leaf and spine data center fabrics and provides a platform for experimenting with analytics driven feedback control using the sFlow-RT hybrid OpenFlow controller.
First build an Ubuntu 13.04 / 13.10 virtual machine then follow instructions for installing Mininet - Option 3: Installation from Packages.
Next, install an Apache web server:
sudo apt-get install apache2Install the sFlow-RT integrated hybrid OpenFlow controller, either on the Mininet virtual machine, or on a different system (Java 1.6+ is required to run sFlow-RT):
Continue reading
Configuring Mellanox switches
The following commands configure a Mellanox switch (10.0.0.252) to sample packets at 1-in-10000, poll counters every 30 seconds and send sFlow to an analyzer (10.0.0.50) using the default sFlow port 6343:sflow enableFor each interface:
sflow agent-ip 10.0.0.252
sflow collector-ip 10.0.0.50
sflow sampling-rate 10000
sflow counter-poll-interval 30
interface ethernet 1/1 sflow enableA previous posting discussed the selection of sampling rates. Additional information can be found on the Mellanox web site.
See Trying out sFlow for suggestions on getting started with sFlow monitoring and reporting.
DDoS mitigation hybrid OpenFlow controller
This article describes an additional example, using the sFlow-RT controller to implement the ONS 2014 SDN Idol winning distributed denial of service (DDoS) mitigation solution - Real-time SDN Analytics for DDoS mitigation.
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| Figure 1: ISP/IX Market Segment |
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| Figure 2: Novel DDoS Mitigation solution using Real-time SDN Analytics |
// Define large flow Continue reading
Cisco, ACI, OpFlex and OpenDaylight
In, Cisco Submits Its (Very Different) SDN to IETF & OpenDaylight, SDNCentral editor Craig Matsumoto comments, "You know how, early on, people were all worried Cisco would 'take over' OpenDaylight? This is pretty much what they were talking about. It’s not a 'takeover,' literally, but OpFlex and the group policy concept steer OpenDaylight into a new direction that it otherwise wouldn’t have, one that Cisco happens to already have taken."
CIMI Corp. President, Tom Nolle, remarks "We’re all in business to make money, and if Cisco takes a position in a key market like SDN that seems to favor…well…doing nothing much different, you have to assume they have good reason to believe that their approach will resonate with buyers." - Cisco’s OpFlex: We Have Sound AND Fury
This article will look at some of the architectural issues raised by Cisco's announcement based on the following documents:
- OpenDaylight: Project Proposals:Group Based Policy Plugin
- IETF: OpFlex Control Protocol
Integrated hybrid OpenFlow control of HP switches
The previous article provided an example of large flow marking using an Alcatel-Lucent OmniSwitch 6900 switch. This article discusses how to replicate the example using HP Networking switches.
At present, the following HP switch models are listed as having OpenFlow support:
- FlexFabric 12900 Switch Series
- 12500 Switch Series
- FlexFabric 11900 Switch Series
- 8200 zl Switch Series
- HP FlexFabric 5930 Switch Series
- 5920 Switch Series
- 5900 Switch Series
- 5400 zl Switch Series
- 3800 Switch Series
- HP 3500 and 3500 yl Switch Series
- 2920 Switch Series
HP's OpenFlow implementation supports integrated hybrid mode - provided the OpenFlow controller pushes a default low priority OpenFlow rule that matches all packets and applies the NORMAL action (i.e. instructs the switch to apply default switching / routing forwarding to the packets).
In Continue reading
Performance optimizing hybrid OpenFlow controller
This article discusses the evolving architecture of software defined networking (SDN) and the role of analytics and traffic engineering. InMon's sFlow-RT controller is used to provide practical examples of the architecture.
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| Figure 1: Fabric: A Retrospective on Evolving SDN |
First generation SDN controllers were designed before the edge / core split became Continue reading