Route Distinguishers and Route Targets

People new to MPLS VPN are often unclear on what functions route distinguishers and route targets serve, and the difference between the two. Let's see if we can clear up some of that confusion. If you could use a refresher on VRF fundamentals, I encourage you to first check out my earlier articles on the topic, Intro to VRF lite and Inter-VRF Routing with VRF Lite.

Route Distinguisher

As you know, VRFs allow IP address space to be reused among isolated routing domains. For example, assume you have to connect to three customer sites, all of which are using 192.168.0.0/24 as their local network. We can assign each customer its own VRF so that the overlapping networks are kept isolated from one another in their respective routing domains.

This works well, but we need a way to keep track of which 192.168.0.0/24 route belongs to which customer. This is where route distinguishers come in. As its name implies, a route distinguisher (RD) distinguishes one set of routes (one VRF) from another. It is a unique number prepended to each route within a VRF to identify it as belonging to that particular VRF or customer. Continue reading

Angry SDN hipsters.

Some folks seem to get a little too hung up on one philosophy or another -- too blind to see good in any other form except the notions that have evolved in their mind.  I'm hoping I'm not one of them.  I do have opinions, but which I believe are rational.

The counter culture of networking waves the SDN banner.  That acronym seems to belong to them.  They don't know what it stands for yet, but one thing they seem to be sure of is that nothing good can come by allowing networking innovations to evolve or even to exist in their birthplace.

The way I see evolving the network fabric is through improving on the best of the past.  Every profession I know from medicine, finance, law, mathematics, physics, you name it -- all of them are building their tomorrow on a mountain of past knowledge and experience.  So I'm sure my feeling the same about the network doesn't make me outdated, just maybe not a fashionable SDN hipster.




Some angry SDN hipsters say that the core network needs to be dumbed down.  They must have had a "bad childhood," technically speaking.  One too many Cisco 6500's stuffed with Continue reading

Service Profiles and Service Profile Templates in Cisco UCS PowerTool

I had a few scripts that were written WAY before PowerTool was out of beta, and the only way I knew how to generate a Service Profile Template was to use manual XML calls. For instance: $cmd = "<configConfMos inHierarchical='true'> <inConfigs> <pair key='org-root/org-" + $orgName + "/ls-" + $serviceProfileName + "' > <lsServer agentPolicyName='' biosProfileName='' bootPolicyName='" + $bootPolicyName + "' descr='' dn='org-root/org-" + $orgName + "/ls-" + $serviceProfileName + "' dynamicConPolicyName='' extIPState='none' hostFwPolicyName='' identPoolName='" + $UUID_POOL_NAME + "' localDiskPolicyName='default' maintPolicyName='default' mgmtAccessPolicyName='' mgmtFwPolicyName='' name='" + $serviceProfileName + "' powerPolicyName='default' scrubPolicyName='' srcTemplName='' statsPolicyName='default' status='created' type='initial-template' usrLbl='' uuid='0' vconProfileName=''> <vnicEther adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' mtu='1500' name='" + $VNIC_A_NAME + "' nwCtrlPolicyName='' nwTemplName='" + $VNIC_TEMPLATE_A_NAME + "' order='3' pinToGroupName='' qosPolicyName='' rn='ether-" + $VNIC_A_NAME + "' statsPolicyName='default' status='created' switchId='" + $switchId + "'> </vnicEther> <vnicEther adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' mtu='1500' name='" + $VNIC_B_NAME + "' nwCtrlPolicyName='' nwTemplName='" + $VNIC_TEMPLATE_B_NAME + "' order='4' pinToGroupName='' qosPolicyName='' rn='ether-" + $VNIC_B_NAME + "' statsPolicyName='default' status='created' switchId='" + $switchId + "'> </vnicEther> <vnicFcNode addr='pool-derived' identPoolName='" + $WWNN_POOL_NAME + "' rn='fc-node' > </vnicFcNode> <vnicFc adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' maxDataFieldSize='2048' name='" + $VHBA_A_NAME + "' nwTemplName='" + $VHBA_TEMPLATE_A_NAME + "' order='1' persBind='disabled' persBindClear='no' pinToGroupName='' qosPolicyName='' rn='fc-" + $VHBA_A_NAME + "' statsPolicyName='default' status='created' Continue reading

Cisco VM-FEX and the Nexus 1000v

Many of those that have supported a vSphere-based virtualization infrastructure for any length of time have probably heard of the Cisco Nexus 1000v. I’ve written a few posts that mention it, and I’ve been deploying the product quite successfully for the past few years. Even cooler, the Nexus 1000v is now available for Hyper-V as well. For those that are not familiar with the idea of distributed switches in general, I’ll overview the concept briefly.

Service Profiles and Service Profile Templates in Cisco UCS PowerTool

I had a few scripts that were written WAY before PowerTool was out of beta, and the only way I knew how to generate a Service Profile Template was to use manual XML calls. For instance: $cmd = "<configConfMos inHierarchical='true'> <inConfigs> <pair key='org-root/org-" + $orgName + "/ls-" + $serviceProfileName + "' > <lsServer agentPolicyName='' biosProfileName='' bootPolicyName='" + $bootPolicyName + "' descr='' dn='org-root/org-" + $orgName + "/ls-" + $serviceProfileName + "' dynamicConPolicyName='' extIPState='none' hostFwPolicyName='' identPoolName='" + $UUID_POOL_NAME + "' localDiskPolicyName='default' maintPolicyName='default' mgmtAccessPolicyName='' mgmtFwPolicyName='' name='" + $serviceProfileName + "' powerPolicyName='default' scrubPolicyName='' srcTemplName='' statsPolicyName='default' status='created' type='initial-template' usrLbl='' uuid='0' vconProfileName=''> <vnicEther adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' mtu='1500' name='" + $VNIC_A_NAME + "' nwCtrlPolicyName='' nwTemplName='" + $VNIC_TEMPLATE_A_NAME + "' order='3' pinToGroupName='' qosPolicyName='' rn='ether-" + $VNIC_A_NAME + "' statsPolicyName='default' status='created' switchId='" + $switchId + "'> </vnicEther> <vnicEther adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' mtu='1500' name='" + $VNIC_B_NAME + "' nwCtrlPolicyName='' nwTemplName='" + $VNIC_TEMPLATE_B_NAME + "' order='4' pinToGroupName='' qosPolicyName='' rn='ether-" + $VNIC_B_NAME + "' statsPolicyName='default' status='created' switchId='" + $switchId + "'> </vnicEther> <vnicFcNode addr='pool-derived' identPoolName='" + $WWNN_POOL_NAME + "' rn='fc-node' > </vnicFcNode> <vnicFc adaptorProfileName='VMWare' addr='derived' adminVcon='any' identPoolName='' maxDataFieldSize='2048' name='" + $VHBA_A_NAME + "' nwTemplName='" + $VHBA_TEMPLATE_A_NAME + "' order='1' persBind='disabled' persBindClear='no' pinToGroupName='' qosPolicyName='' rn='fc-" + $VHBA_A_NAME + "' statsPolicyName='default' status='created' Continue reading

Cisco VM-FEX and the Nexus 1000v

Many of those that have supported a vSphere-based virtualization infrastructure for any length of time have probably heard of the Cisco Nexus 1000v. I’ve written a few posts that mention it, and I’ve been deploying the product quite successfully for the past few years. Even cooler, the Nexus 1000v is now available for Hyper-V as well. For those that are not familiar with the idea of distributed switches in general, I’ll overview the concept briefly.

How Can The Tech Interview Help Fill the Technical Career Gap?

It’s only been a couple of short weeks since this site officially launched. I have to say that I’m thrilled with the initial ‘buzz’ around the site. Many friends from various other technical blogs and social networking circles have shared The Tech Interview with their friends. In addition to thanking everyone for sharing this site, […]

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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 How Can The Tech Interview Help Fill the Technical Career Gap? appeared first on Packet Pushers Podcast and was written by Paul Stewart.

ACE Management

Was knocking my head against a brick wall trying to configure an ACE for management for a couple of days. Turns out, it does not permit ICMP to it by default.

This is a good place to start:

http://www.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/admin/guide/access.html#wp1054979

So you need to configure a class map classifying ICMP traffic from specific sources as being interesting, a policy map referencing the class map, an action for matching traffic and then apply that using the “service-policy” command to the interface you want to permit traffic to.

Everything is well as long as it’s only management traffic you want to permit to this address.


Thinking About SDN Packet Processing: You’re the One Talking to a Fish

Barbie films (yes, I really am talking about Barbie in a network blog post) are a big hit with my kids, and surprisingly with me too. I’ll possibly regret telling the world that, but anyway, there’s an exchange in one film* that always make me laugh. It goes like this. Human (Australian accent): “You’re bonkers!” […]

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Steven Iveson

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 Thinking About SDN Packet Processing: You’re the One Talking to a Fish appeared first on Packet Pushers Podcast and was written Continue reading

Don’t use 192.168.1.0/24 on work LAN

How does the internet work - We know what is networking

This story will be a turning point for my blog future starting with a change in writing methods and changing those methods to a more causal fashion. INTRO For now all my text here where somehow depersonalized and tech oriented in a way that it was all written like in some book. User manual to me concise. Maybe this […]

Don’t use 192.168.1.0/24 on work LAN

The Attributes of a Great CLI

So, there I was, innocently browsing the OpenDaylight wiki after listening to Show 148 – Talking With OpenDaylight Leadership when I came across the OpenDaylight Command Line Interface page. I’ve not gone through the entire 118 pages (if I were to print it) worth of content, but I’ve scanned through a fair chunk and read the CLI Concepts section in […]

Author information

Steven Iveson

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.

TwitterLinkedIn

The post The Attributes of a Great CLI appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Networking at Cisco Live for Your Technical Career

Cisco Live is a wonderful opportunity to meet people and have in-depth technical discussions. For me, I find this event to be a great venue to finally see those that I have had numerous online interactions with. It serves as a way to elevate these relationships to a new level. In John’s article entitled “Build […]

Author information

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 Networking at Cisco Live for Your Technical Career appeared first on Packet Pushers Podcast and was written by Paul Stewart.

Fun With Unmanaged Switches + Port Security

I’ve just passed a year of my job working at a smallish non-profit, and one part that I really am enjoying is passing on knowledge to the front-line staff. This week, there was an interesting case, and I had to explain to my colleagues what was happening and why. So, I did a little demo, and […]

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Matthew Mengel

Matthew was a Senior Network Engineer for a regional educational institution in Australia for over 15 years, working with Cisco equipment across many different product areas. However, in April 2011 he resigned, took seven months of long service leave to de-stress and re-boot before becoming a network engineer for a medium sized non-profit organisation. At the end of 2013, he left full-time networking behind after winning a scholarship to study for a PhD in astrophysics. He is on twitter infrequently as @mengelm.

The post Fun With Unmanaged Switches + Port Security appeared first on Packet Pushers Podcast and was written by Matthew Mengel.

Straight talk about the enterprise data center network.


Building a mission critical system requires the careful selection of constituent technologies and solutions based on their ability to support the goals of the overall system.   We do this regardless of whether we subscribe to one approach or another of building such a system.

It is well known that the network technologies commonly used today to build a data center network have not adequately met the needs of applications and operators.  However, what is being drowned out in the media storm around "SDN" is that many of the current day challenges in the data center network can be addressed within an existing and familiar toolkit.  The vision of SDN should be beyond where today’s data center networks could have been yesterday.

In this "treatise" I highlight what I believe has been lacking in todays data center core network toolkit as well as address certain misconceptions.  I'll begin by listing key aspects of a robust network, followed by perspectives on each.  

A robust network should be evolved in all of the following aspects:
  1. Modularity - freedom to choose component solutions based on factors, such as bandwidth, latency, ports, cost, serviceability, etc.,  This generally requires the network to Continue reading

Don’t Hate the Player, Hate the Tools

The other day I came across an article, “Industry execs: Network admins an endangered species,” and I have to say, the headline did its job. I had to read more.

Executives from HP and Juniper, in particular, contend that network virtualization, and specifically Software-Defined Networking (SDN), will bring new levels of automation to networks, which in turn will lower operational costs because network administrators will no longer be needed. Specifically, their argument is that administrative or “people” expense is much higher than equipment costs, so automating will eliminate significant expense.

That’s one way to look at it I suppose. However, I would suggest that automation presents new opportunities for the networking team.

It is true that achieving significant OPEX savings is a key part of our discussion with customers when we talk about Embrane’s network services automation solutions that are being implemented today in enterprise data centers. However, we don’t talk about it in the context of, “how many heads can I cut?” Instead,  our conversations center around how our customers can best use the people they have, and what tools are needed to enable the right level of talent to perform the right tasks.

The reason we’re having Continue reading

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