Hot,Cold, Mash Potato Routing and BGP Route Reflector Design Considerations.

If someone tosses you a hot potato, do you want to hold it a long time?  If you like pain maybe the answer is yes – but how many of us like pain?  In the same way, hot potatoes are very applicable to the Service Provider environment. When a service provider receives a packet, if […]

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Orhan Ergun

Orhan Ergun, CCIE, CCDE, is a network architect mostly focused on service providers, data centers, virtualization and security.

He has more than 10 years in IT, and has worked on many network design and deployment projects.

In addition, Orhan is a:

Blogger at Network Computing.
Blogger and podcaster at Packet Pushers.
Manager of Google CCDE Group.
On Twitter @OrhanErgunCCDE

The post Hot,Cold, Mash Potato Routing and BGP Route Reflector Design Considerations. appeared first on Packet Pushers Podcast and was written by Orhan Ergun.

MPLS VPNs and Junos config groups: a match made in router heaven

Introduction If you manage MPLS VPNs on Juniper Networks devices running Junos (or are learning about doing so), this tip should make your life easier. I can’t imagine operating MPLS VPNs on a scale of more than a handful of VPNs without it. Below I’ll describe how it works, and then to make sure it’s […]

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Nik Weidenbacher

Nik has been into linux, networking and software development for the past couple of decades. He's been working for a service provider for a long time, and in recent years has been doing a lot with data center automation (the buzzword-enhanced version of that being "cloud orchestration").

The post MPLS VPNs and Junos config groups: a match made in router heaven appeared first on Packet Pushers Podcast and was written by Nik Weidenbacher.

IPSec Bandwidth Overhead Using AES

Someone asked so lets walk through the overhead introduced when using IPSec with AES; it’s higher than you might think and I haven’t even factored in ISAKMP. Encryption really isn’t ‘my bag’ so if anything is wrong, do let me know; hopefully public scrutiny will mean I can truly rely on these figures. Take a […]

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Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

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The post IPSec Bandwidth Overhead Using AES appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Not-Via? Not-What?

In our last episode (it’s been two weeks!), we talked about P’s and Q’s. Now we’ll get down into a few details, and think through what is probably the simplest mechanism ever designed for finding alternate loop free paths through a two connected network: not-via. Let’s use the embedded network as an example. In this […]

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Russ White

Principle Engineer at Ericsson

Russ White is a Network Architect who's scribbled a basket of books, penned a plethora of patents, written a raft of RFCs, taught a trencher of classes, and done a lot of other stuff you either already know about, or don't really care about. You want numbers and letters? Okay: CCIE 2635, CCDE 2007:001, CCAr, BSIT, MSIT (Network Design & Architecture, Capella University), MACM (Biblical Literature, Shepherds Theological Seminary). Russ is a Principal Engineer in the IPOS Team at Ericsson, where he works on lots of different stuff, serves on the Routing Area Directorate at the IETF, and is a cochair of the Internet Society Advisory Council. Russ will be speaking in November at the Ericsson Technology Day. he recently published The Art of Network Architecture, is currently working on a new book in the Continue reading

Show 164 – Cool or Hot? Lapukhov + Nkposong’s BGP SDN

On this Packet Pushers podcast, hosts Ethan Banks and Greg Ferro are joined by Petr Lapukhov for a discussion about his IETF draft on BGP SDN, co-authored with Edet Nkposong. Guests Russ White and Ivan Pepelnjak also join in the discussion, quizzing Petr about the details of the draft and how implementation has worked out thus far […]

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Ethan Banks

Co-host at Packet Pushers

Ethan Banks, CCIE #20655, has been managing networks for higher ed, government, financials and high tech since 1995. Ethan co-hosts the Packet Pushers Podcast, which has seen over 2M downloads and reaches over 10K listeners. With whatever time is left, Ethan writes for fun & profit, studies for certifications, and enjoys science fiction. @ecbanks

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The post Show 164 – Cool or Hot? Lapukhov + Nkposong’s BGP SDN appeared first on Packet Pushers Podcast and was written by Ethan Banks.

IPv6 multicast over IPv6 IPSec VTI

Introduction to Open vSwitch

Introduction to Open vSwitch

OSPF Adjacency Building Process

Ever curious regarding how two routers configured for OSPF become fully adjacent?  The following diagram of the process was modeled directly from RFC 2328, and the steps described gleaned from the Routing TCP/IP Vol I book.  Since we can see mention of a DR, this example must be based on a multi-access network.

1. RT1 becomes active and sends a Hello.  At this point, RT1 hasn’t seen any neighbors, so it reports such and sets its DR and BDR fields to 0.0.0.0.
2. Upon receipt by RT2, RT2 will build a data structure for RT1 and set RT1’s state to Init.  RT2 will then send a Hello packet reporting that it has seen RT1, and will report itself as the DR.
3. RT1 now sees its own RID in the received Hello packet from RT2, so RT1 will now create a data structure for RT2 and set its state to ExStart.  RT1 then begins Master/Slave negotiation with a DD packet with a sequence number of “x”, the Init bit set  to indicate that it is the start of an exchange, the More bit set to indicate that it is not the last DD packet to Continue reading

Quiz #19 &#8211 Short Network Cuts with MSTP

As a senior network administrator, you receive complaints from server team that yesterday there were multiple short network cuts that impacted some very sensitive applications running in the data center. You investigate and find out that one of the level 1 network engineers performed some network changes. What went wrong?

Product & Routing Webinar: Multicast

Packet Design will be hosting a Product & Routing Webinar focused on Multicast on Wednesday, October 23 at 3pm CST. The event will feature Matt Sherrod, VP of Product Management, as its key speaker and will leave time after the live demonstration for Q&A. 

Register to attend here

OVSDB Echo in Python

OVSDB Echo in Python

OSPF Link State Advertisements (LSAs) and Areas – Part II

For a table describing the different LSA types, check out the first post of this series.

In the first part of the series, we looked at LSA Types 1, 2, and 3 – Router, Network, and Network Summary, respectively.  To move on to the next two LSA types, we need to bring in another Autonomous System (AS).  In the diagram below, we’ve added R5 which has an interface in EIGRP AS 1, and is redistributing that into OSPF Area 4.  The fact that R5 has an interface inside of the OSPF AS, as well as the EIGRP AS, makes R5 an Autonomous System Boundary Router (ASBR). 

The EIGRP-oriented subnet that is being redistributed is considered an external route to the OSPF domain, so a Type 5 LSA, or ASBR External, is flooded into OSPF Area 4 containing a LSID and netmask of the subnet, plus the External Type. This important because it tells other routers whether or not to add the internal link costs within the OSPF domain to the metric to reach that subnet.  A type 2 external route specifies that only the external cost is taken into consideration.

When R2 catches wind of Continue reading

Making sense of Broadband networks – VLAN Model

Understanding IPv4 uRPF on Junos DPC/MPC

Understanding IPv4 uRPF on Junos DPC/MPC

Understanding IPv4 uRPF on Junos DPC/MPC

Why so Rude?

The engineering world has a long standing tradition none of us should be too proud of: rudeness. There was, in fact, a time when I was working the phones on customer support that the general attitude was, “feel free to flame me when I ask a question, just answer the question in the flame.” Flames […]

Author information

Russ White

Principle Engineer at Ericsson

Russ White is a Network Architect who's scribbled a basket of books, penned a plethora of patents, written a raft of RFCs, taught a trencher of classes, and done a lot of other stuff you either already know about, or don't really care about. You want numbers and letters? Okay: CCIE 2635, CCDE 2007:001, CCAr, BSIT, MSIT (Network Design & Architecture, Capella University), MACM (Biblical Literature, Shepherds Theological Seminary). Russ is a Principal Engineer in the IPOS Team at Ericsson, where he works on lots of different stuff, serves on the Routing Area Directorate at the IETF, and is a cochair of the Internet Society Advisory Council. Russ will be speaking in November at the Ericsson Technology Day. he recently published The Art of Network Architecture, is currently working on a new book in the Continue reading

The Importance of Setting Expectations

One of my first experiences dealing with a technology customer involved a request to deliver and install a new PC and printer. During the process I expected I would need to educate the user on the features of Windows 3.1. This was before I ever really started working in technology in a full-time capacity. While […]

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Paul Stewart

Paul is a Network and Security Engineer, Trainer and Blogger who enjoys understanding how things really work. With nearly 15 years of experience in the technology industry, Paul has helped many organizations build, maintain and secure their networks and systems. Paul also writes technical content at PacketU.

The post The Importance of Setting Expectations appeared first on Packet Pushers Podcast and was written by Paul Stewart.