Let’s return to our simple four AS network to look at a number of issues with BGPSEC — the bits you won’t often hear discussed in just about any forum. Assume, for a moment, that AS65000 advertises some route, say 192.0.2.0/24, to AS65001, and not to AS65002. For whatever reason, a few days pater, the […]
The post BGPSEC: Replays, Timers, and Performance appeared first on Packet Pushers Podcast and was written by Russ White.
A long time ago, Packet Pushers ran an OSPF Design Part 1 show. That show went after the default design guides that network engineers have been reading for years, making the big point that you can scale a single OSPF area quite large indeed. But…that’s not the entire story about OSPF areas. Areas still have their use cases, […]
The post Show 218 – OSPF Design Part 2 appeared first on Packet Pushers Podcast and was written by Ethan Banks.
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
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.
Knowing 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.
This is a common scenario and the solution is straightforward. In Wireshark, right-click any of the packets and choose Decode As…
At this point, a new window will appear. Make sure the Transport tab is selected then choose Do Continue reading
Another week of looking critically and cynically at the technology market, especially networking and storage.
The post Network Break 25 appeared first on Packet Pushers Podcast and was written by Greg Ferro.
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I would like to start by saying Merry Christmas and Happy Holidays season to all. In between spending time with my family, decorating the Christmas three and opening presents, I did find some time to play around with my hobby and testing something in the lab.
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
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’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.
I’ve covered the HP VSR1000 previously. This Continue reading
