How to configure GNS3 installed on Linux to support more than 8 NIC for Qemu Instances

Recently I have read a question on GNS3 forum asking whether Qemu supports more than 8 network adapters. According to Google search, maximum number of adapters for Qemu virtual machines can be configured with a parameter #define MAX_NICS 8 in a file ./include/net/net.h under Qemu source tree. After you set desirable value you must compile and install Qemu from source.

However I have noticed that changing the integer value in the line #define MAX_NICS  has no effect on the maximum number of NIC allowed for Qemu VMs. I notice that I can start Core Linux Qemu machine with 18 network adapters even Qemu 2.2.0 was compiled with parameter #define MAX_NICS set to 1.

Now we know that Qemu itself does not limit the maximum network adapters to 8. We will go ahead and investigate GNS3. Navigate to Edit -> Preferences -> QEMU VMs and click on existing Qemu VM. Click on Edit button for this VM and navigate to Network tab. Increase the number of Adapters to 9.

The GNS3 1.2.1 allows to add maximum 8 NICs for a particular Qemu virtual machine. To avoid this limitation we have edit GNS3 source files and recompile GNS3 GUI and server. Here are the the steps for Linux.

1. Download and extract GNS3 1.2.1 Linux Continue reading

Don’t Let Wireshark’s Assumptions Mislead Your Troubleshooting

In an effort to educate myself on the inner workings of WebEx, I recently looked at a session with Wireshark. Knowing that WebEx audio has the ability to use UDP or TCP, I wanted to isolate the protocol being employed in my configuration. I watched for a new stream of traffic as I enabled the audio portion of a meeting. I found that the audio was using UDP port 9000.

I next applied a filter to see only this traffic. What immediately jumped out at me was what appeared to be malformed and fragmented packets. I also noticed a lot of strange IP addresses like 1.0.0.0, 1.0.0.1, 0.0.0.30, 0.0.0.31 and so on.

WebExUDP9000Knowing that the audio was working perfectly, I could have easily concluded that my eyes were deceiving me. When I looked closer, I quickly realized that Wireshark was recognizing and decoding this as if the packets were Lawful Intercept.

Changing the Decode TypeDecodeAs

This is a common scenario and the solution is straightforward. In Wireshark, right-click any of the packets and choose Decode As…

TransportAt this point, a new window will appear. Make sure the Transport tab is selected then choose Do Continue reading

Group based policy in Opendaylight

This is a continuation of my previous blog on Group based policy(GBP). In this blog, I will cover the GBP features in Opendaylight helium release, Use-cases that are published in the Opendaylight wiki as well as different usecase that I tried out. Group based policy in Opendaylight: Following diagram is from Opendaylight GBP wiki: Openstack here … Continue reading Group based policy in Opendaylight →

Network Break 25

Another week of looking critically and cynically at the technology market, especially networking and storage.

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

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The post Network Break 25 appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Merry Christmas

I wanted to wish my readers a Merry and safe Christmas! If you don’t believe in Christmas, then Happy Hanukkah Happy Kwanzaa, Happy Holidays or whatever else you may believe in. We all need...

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The Next Network Transformation: We have only just begun

Whenever we get to the end of a year we have this tendency to reflect on what has happened in the past year and how we can improve in the coming year. It’s natural to use the change of calendar year as a point in time to think back, even though practically speaking it is usually the most chaotic time of the year between shopping, family and year and quarter end at work.

Almost every industry will go through waves of change and transformation. Real change and transformation is driven by powerful market forces of demand coupled with technology leaps that allow an escape from incremental changes that drive day to day improvements. Networking has gone through several of these transformations. From dedicated main frame based connectivity, to coax based shared ethernet to switches ethernet in local area networks. From 1200 baud dialup serial connections through X.25 (yes, that’s the European in me) to leased T1 to ATM, to Frame Relay, to Packet over SONET to MPLS and various flavors of wide area ethernet services. Some of these were incremental, some of them truly transformational.

When you look back, each of these changes in network technology was very much Continue reading

Resources for learning HP Comware

HP is making more resources available to help with learning Comware. They’ve added free labs and courses to the already published simulators and virtual routers. This is a good resource for those looking to get started with Comware.

HP Network Simulator (HNS, aka Simware)

HP’s Network Simulator (HNS) is a modelling tool for simulating HP Comware networks. It includes Layer-2 functionality, and lets you test things like LACP & IRF. I found it too slow when I first tried it, but this has improved significantly with current versions. It is free to download.

HP has now started publishing simple labs you can work through with HNS:

These are short labs that cover HNS setup, and device configuration. Quick and easy, they show how to use the tool, and give you a taste of Comware configuration. They’ve also released a free 1-hour online course that goes through how to use HNS.

Interestingly, the course is narrated by Natalie Timms, formerly of the CCIE Security Program. She’s popped up a couple of times on Packet Pushers too.

VSR1000

I’ve covered the HP VSR1000 previously. This Continue reading

VMs Running In My ESXi Networking Lab as of 23-Dec-2014

Over the last several months, I’ve been building a lab full of virtual machines related to networking. I am using 2 independent ESXi hosts running vSphere 5.5 running on Haswell motherboards with 32GB of RAM, 256GB local SSDs, and a Synology DS1813+ for big, slow remote storage I access with NFS. You can […]

Dear Leader’s Lesson in Confirmation Bias

Brian Krebs has a blogpost citing those who claim evidence of North Korea involvement in the massive Sony hack. He uses as an example the similarities between the Sony defacement and a South Korean defacement that was attributed to the North Koreans. He shows these two images side-by-side so that you can see that they are obvious similar.


However, they don't look similar at all. This is generally what all website defacements look like. Specifically, the common components among defacements in are:
  • black background
  • green, red, and white foreground
  • "Hacked by" message
  • WARNING banner
  • Phrack-style headers (like ::: on either side of header)
  • Powerful picture in center, often a skull
  • Message that strokes the ego, often "we are legion" style
In the bottom of this post, I include a gallery of other defacement pictures, so that you can see that this is normal hacker underground culture.

There are certainly some similarities, such as the "we have all your data" message. But that's easily explained by the fact that the South Korean hack was widely popularized in the media, so it's easy to see how they would take this as inspiration. Or, it's just simply that if the goal of your Continue reading

REST API for Cumulus Linux ACLs

RESTful control of Cumulus Linux ACLs included a proof of concept script that demonstrated how to remotely control iptables entries in Cumulus Linux.  Cumulus Linux in turn converts the standard Linux iptables rules into the hardware ACLs implemented by merchant silicon switch ASICs to deliver line rate filtering.

Previous blog posts demonstrated how remote control of Cumulus Linux ACLs can be used for DDoS mitigation and Large "Elephant" flow marking.

A more advanced version of the script is now available on GitHub:

https://github.com/pphaal/acl_server/

The new script adds the following features:
  1. It now runs as a daemon.
  2. Exceptions generated by cl-acltool are caught and handled
  3. Rules are compiled asynchronously, reducing response time of REST calls
  4. Updates are batched, supporting hundreds of operations per second
The script doesn't provide any security, which may be acceptable if access to the REST API is limited to the management port, but is generally unacceptable for production deployments.

Fortunately, Cumulus Linux is a open Linux distribution that allows additional software components to be installed. Rather than being forced to add authentication and encryption to the script, it is possible to install additional software and leverage the capabilities of a mature web server such as Apache. Continue reading

Expiring The Internet

An article came out this week that really made me sigh.  The title was “Six Aging Protocols That Could Cripple The Internet“.  I dove right in, expecting to see how things like Finger were old and needed to be disabled and removed.  Imagine my surprise when I saw things like BGP4 and SMTP on the list.  I really tried not to smack my own forehead as I flipped through the slideshow of how the foundation of the Internet is old and is at risk of meltdown.

If It Ain’t Broke

Engineers love the old adage “If it ain’t broke, don’t fix it!”.  We spend our careers planning and implementing.  We also spend a lot of time not touching things afterwards in order to prevent it from collapsing in a big heap.  Once something is put in place, it tends to stay that way until something necessitates a change.

BGP is a perfect example.  The basics of BGP remain largely the same from when it was first implemented years ago.  BGP4 has been in use since 1994 even though RFC 4271 didn’t officially formalize it until 2006.  It remains a critical part of how the Continue reading

Happy Holidays from Packet Design

Happy Holidays from Packet Design

by Patrick Kilgore, Interactive Marketing Manager - December 23, 2014

It is that time of year again… and what a difference a year makes! We grew leaps and bounds in 2014, increasing our headcount as an organization and working hard to provide our customers with the best in route analytics technology.

To give back for all our good fortune in 2014, we adopted two families in the Austin area and provided additional "cheer" to make their holidays bright. Everyone at Packet Design came together to donate gifts and their time, and we could not have been happier at the participation in such a worthy endeavor. Packet Design would like to extend a special thanks to Angela Reyna, a key member of our marketing team, for putting it all together. It is moments like these that give us pause to remember that people, working as a team, make our organization a success. So from our Packet Design family to yours, we wish you Happy Holidays and a spirited New Year!

Below are photos from our wrapping party, where the Packet Design elves showed off their gift-wrapping and logistics skills:

Automating Cisco Nexus Switches with Ansible

In previous posts, I’ve written about using Ansible for network automation.  Few of them can be found here, here, here, and here.  In one of the posts, I had a video that was automating Cisco routers with Ansible, and was using onePK as the API to communicate to the device.  In this post, I’ll be focusing on automating Nexus switches – this means each of the Ansible modules will be using NX-API to communicate with the device.  This also eliminates the need for the users of these modules to know Python as they’ll be using the Ansible platform for their specific automation needs.
While the demo below is for configuration automation and shows what can be done in just a few seconds, it needs to be understood that automation is much more than pushing configurations.  I hope to show some of this first hand by doing more interesting things as it pertains to data gathering, verification, troubleshooting, that do increase speed and agility, but also predictability.

The following video shows how Ansible can be used to automate interfaces and VLANs on Nexus switches.   This will be the first in a Continue reading

PQ Show 38 – HP Networking, Helion, OpenStack and Cloud Networking

HP Helion is the cloud platform HP is bringing to Enterprise for private cloud and used by HP to build their Helion public cloud. In this show, recorded at HP Discover as part of our show coverege, we talk about Virtual Cloud Network (VCN) for OpenStack that uses OpenFlow and OVSDB as a basis for implementing features in the physical network in OpenStack and Helion.

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

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The post PQ Show 38 – HP Networking, Helion, OpenStack and Cloud Networking appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Merry Christmas to the PacketU Community

I wanted to take a moment to wish all PacketU readers a Merry Christmas and a Happy New Year. With that, I leave you with a short video clip of my son playing Silent Night at a church program last week. Longtime friends know that we had a pretty serious health scare with him 5 years ago and we count ourselves very blessed to have him in our lives.

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