In this first part of the Multicast Design and Deployment Series, Orhan Ergun talks with Mr. Multicast Beau Williamson about many multicast concepts. They both start from the basic and deep dive many multicast concepts while giving real life examples.
The post Community Show – Multicast Design and Deployment Considerations with Beau Williamson and Orhan Ergun appeared first on Packet Pushers.
In this first part of the Multicast Design and Deployment Series , Orhan Ergun talks with Mr.Multicast Beau Williamson about many multicast concepts. They both start from the basic and deep dive many multicast concepts while giving real life examples. Why Multicast?. What are the general use cases in real life ? Layer 2 […]
The post Community Show – Multicast Design and Deployment Considerations with Beau Williamson and Orhan Ergun appeared first on Packet Pushers Podcast and was written by Orhan Ergun.
Lately I have done some studying for the CCDE and one of the things I was
looking at is how to protect against DDoS attacks. I’m not expecting it
to be a big topic for the CCDE but it has some interesting concepts relating
to routing. Take a look at the following topology:
There is an attacker at the top left. R1 is the edge device and then there are a
few more routers, all peering BGP with the RR, which is R5. The server of interest
is 100.100.100.100 and there is a scrubbing device to the far right. All routers
peer iBGP from their loopbacks to the RR, including the scrubbing device.
Normally traffic to 100.100.100.100 would flow through R1 to R4 and then to the
server.
The attacker now starts to flood the server with malicious traffic. This is detected
by the DDoS scrubbing device which starts to announce via BGP a more specific route
than the one advertised by R4. R4 normally advertises 100.100.100.0/24 but the
scrubbing device advertises 100.100.100.100/32. All the other routers will start
to forward traffic to 100.100.100.100 towards Continue reading
Let’s get an IPv4 default route into EIGRP. There are a few methods to do it. I hate most of them, though. I think it will be obvious which one I like.
Here’s the lab I have set up to test everything. I want R4 to generate the default in each case.
Default Network – Candidate default. I don’t think I’ve ever used that all my years in networking, but here’s how to use it in EIGRP for a default route. You basically say “If you don’t know where to send a packet, send it to where network X lives.” We’re going to set the 192.168.1.0/24 as the default network, so, in our case X = 192.168.1.0. R4 will tag that route as a default candidate when it advertises it to the rest of the network. The config is easy but requires a stateful (yes, stateful) network to beconfigured as the default.
R4 config: R4(config)#ip default-network 192.168.1.0 ! R1 routes: R1#sh ip route ... 4.0.0.0/24 is subnetted, 1 subnets D 4.4.4.0 [90/435200] via 192.0.2.3, 00:08:33, FastEthernet0/0 [90/435200] via 192.0.2.2, Continue reading
I know many have been [not so patiently] waiting for the arrival of a Cisco virtual lab. Although I haven’t heard any official release date for VIRL or CML, there is a small scale virtual router lab available today. This lab is the All-in-One Virtual Machine made available on the Cisco DevNet site.
While not a comprehensive lab, it is a quick and easy way to get some real command line experience or test smaller layer 3 challenges. This VM includes 3 routers with a total of 10 routed interfaces in use. There is no access to layer 2, so the topology can only be manipulated by shutting down interfaces on the routers.
This product downloads as an OVA file. The file is easily imported into VMWare. In my case, I used VMWare Fusion running on OSX. Once downloaded and imported, the VM is launched like any other virtual machine. As it boots, you will notice that this is running in Ubuntu. The initial credentials are cisco/cisco123 and the operating will prompt to change the password.
Once installed and logged in, you will be Continue reading
I have a lot of discussions with vendors, peers and other friends in the business. One of the things that I find challenging is the nuances with the language of technology. Our conversations include things like traffic flow, NAT, SDN, Cloud and many of the other industry buzzwords. Our use of terminology often has different meanings to different people (and in different contexts).
While I don’t fully subscribe to the, There is no bad question philosophy, I believe questions should be asked liberally. The only questions I hate to hear are from those trying to prove their [superior] knowledge. Beyond that, individual research can help with the learning process. However, everyone should have the confidence to ask those questions necessary to grasp the conversation at hand. More than likely others will benefit from the clarification as well.
The post Asking for Clarity appeared first on PacketU.
The IP PBX business is shrinking as mobile phones replace desk phones. More importantly, voice calls are replaced with chat applications like Skype, FaceTime, SnapChat. Modern companies are using messaging platforms like Slack to replace time wasting telephone calls – we run the Packet Pushers business zero telephone calls. I’ve been predicting this for a year […]
The post Response: IP PBX sales decline 10% | Dell’Oro appeared first on EtherealMind.
I’ve initially joined Juniper Networks in 2001 and over the years i’ve had the opportunity to establish a relationship with a few of the field people, specially in Europe where i just happen to know a lot of the old timers that built up Juniper’s business in the region.
Over the past few weeks i’d a couple of conversations with some of them that forced me to try to distill my perspective on the current trends in the networking industry to a small set of observations. Often the question that starts the conversation is how I see the applicability of OpenStack and OpenContrail to the key networking markets: carrier, enterprise and cloud/content provider. The question often implies a certain doze of healthy skepticism.
OpenStack and OpenContrail are tools; the evolution that we are seeing at that moment in the industry is deeper than that.
The traditional workflow for a network deployment is to go through architecture, design and operations phases. Traditionally the architecture group selects the top level goals and the technology approach for the deployment and produces an architecture document; from that document the design team then starts working on qualification of equipment, detailed design and operational guide; when Continue reading
I’ve been reading articles by Jeremy Stretch for several years now. His site, PacketLife.net, may be best know for the useful cheat sheets that cover everything from IGP routing protocols to Wireshark Display filters. This site doesn’t end with cheat sheets. It also has many useful articles about all things networking. So if you’re looking for a site to add to you feedreader, check it out.
Disclaimer–I continually get requests for a list of the blogs, podcasts and people I follow to “keep up” in this industry. As a result, I decided to start publishing some of the blogs I regularly read. Links to other content from PacketU or affiliated social channels should not be thought of as a universal endorsement or indication of independence or neutrality for a given external site. Readers should assess ALL applicable content before proceeding with actions that could adversely affect their environment.
The post Continue reading
Lots of people claiming that scripting works for automation and, for a few scripts or tasks, you can get a lot done for not much effort. My experiences with scripting have left me bitter and jaded. Here is why.
The post Scripting Does Not Scale For Network Automation appeared first on EtherealMind.
Extreme Network now charges a license fee for ports that have 40G/100G OEM or third party SFPs installed. If you don't purchase a license within 90 days, it will limit bandwidth to 25%. How crappy is that ? Hiding the full price of the switch in SFP pricing strategies is a dumb idea that all the vendors have, what about simply being honest and calling it what it is - a per-port licensing fee designed to extract more revenue from a shrinking market.
The post Response: Extreme Charges License Fee When Using OEM SFPs, Limits Bandwidth appeared first on EtherealMind.
Health week on the Coffee Break - we are drinking water instead of coffee or kool-aid. Everything else remains the same.
The post Coffee Break -Show 11 appeared first on Packet Pushers.
Health week on the Coffee Break - we are drinking water instead of coffee or kool-aid. Everything else remains the same.
The post Coffee Break -Show 11 appeared first on Packet Pushers Podcast and was written by Greg Ferro.
