A Network Blog by a Network Engineer

Tech Field Day – Network Field Day #2

Jeff Fry published on 2011-10-05 included in Tech Field Day

I just got my invitation to the next Tech Field Day, well actually Network Field Day #2, and I cannot tell you how excited I am, as well as humbled to be asked to attend.
My first experience with Tech Field Day was back in February of this year when I attended Tech Field Day #5. That event was more data center focused and was something that I will never forget. I learned quite a bit about a lot of technologies and companies that I was not overly familiar with. It was amazing to see how far some of the technology has come so fast, it was just mind melting. There where some topics that where right up my alley with regards to expertise, and those I learned even more about. It was an experience that I was hoping I would get a chance to experience again, and thankfully I will.

Home Virtualization and Learning

Jeff Fry published on 2011-09-15 included in Cool Technology

Cables in box

As some of you have seen on my Twitter feed, I am playing with some home virtualization ideas. By Home Virtualization I am referring to running ESXi Hyper-visor at home for my “servers” as well as trying to see if I can virtualize the families computers. This is an interesting concept that comes with some unique challenges, and a few of them I am still trying to figure out!
The server part has been the easy one, just did a Physical to Virtual (P2V) conversion via the free tool VMware vCenter Converter at VMWare – link. The tool will allow you to take a currently running server and convert it to a Virtual machine on your ESXi server. I moved my families Domain Controller / DNS server over, powered it on in the VMware console application, then powered off the physical box. Once the IP address was moved to the new server, everything just worked.

Curious note on the P2V tool. I have also used this when I purchased a new computer or fix a friends computer. I will P2V the computer first, this way no matter what happens I can still spin up the old computer under VMPlayer – link. When I get a new computer I just copy the Virtual Machine to my new computer so that I can access all the old software and such whenever I need to. If I need to see how something was configured, just launch the VM and take a look. It is an snapshot in time of the old computer.

Basic MPLS continued – RIP

Jeff Fry published on 2011-09-12 included in CCIE IOS

The other day I posted some “basic” MPLS information and figured I could use that to build a bit more. In subsequent posts I will post the configs for EIGRP, OSPF, and BGP – but today I will post on RIP.
So, this whole lab/post will build off the previous one – LINK – but will remove all the static routes and replace them with the RIP protocol. I will only post the configs for the CE (R1, R3, R4, R5) and PE (R2 and R5), the core will not change.

MPLS RIP

Basic MPLS with VRF, RD, and BGP VPNv4

Jeff Fry published on 2011-09-09 included in CCIE How To

funny-cats-2-225x300

Since I am starting out my SP studies again I figured I would do a post on basic MPLS VPNs with VRFs and just use static routes. These are some of the base fundamentals in a MPLS VPN deployment, and from here you can quickly build out and add complexities if you wish. What I will cover here is VRF, RD, LDP, and MP BGP configurations and I will start by defining and explaining the technologies.
Virtual Routing and Forwarding, or VRF for short, is a technology that allows a router to have multiple instances of a routing table at the same time. These routing tables co-exist on the router, but yet are segmented and independent of each other. An analogy would be Server virtualization. You can have a single server running VMWare, and then under that have multiple instances of Windows running independently of each other. You can configure those servers to talk to each other, or completely isolate them away and they will have no knowledge of each other.
A Route Distinguisher, or RD, is a way to identify a VPN route in an MPLS network. What this does is add an 8-byte value to an IPv4 prefix to create a VPNv4 prefix, typically referred to as an VPN-IPv4 address. Since each customer is assinged a unique RD, their addresses are guaranteed to be unique. So if you have Customer A that has a 10/8 address space and Customer B that also has a 10/8 address space, the addition of the RD brings uniqueness to each of them. A RD looks nomally looks like 1:100

CCIE Service Provider v3

Jeff Fry published on 2011-09-08 included in CCIE

I know I missed it and it seems as though others might have missed it as well. So I figured I would take a moment and share the news – INE will be having CCIE Service Provider 3.0 Workbooks, Classes, and best of all, RACKS!
Last Friday, September 2nd, Brian McGahan posted on the INE blog the information – you can read the post here – LINK. From what his post says, their topology will consists of 20 routers including two GSR 12000 running IOS XR 3.9.1 as well as a pair of Metro-E 3400 switches. The rest of the routers are a mix of 7200VXR and 2600XM routers.
I am assuming that the 2600 series routers will be the CE devices, the 7200 will be the PE and the 12000 will be in the core. This hardware lists closely resembles the hardware list Cisco has provided, minus the Cisco 7600 routers (but those and the 7200 on the actual lab are Simulators).
In case you are wondering what is all on the lab, here is the list from Cisco’s CCIE SP Page – Link (login required)
1. Implement, Optimize and Troubleshoot Core IP Technologies
_1.1. Packet over SONET
_ 1.1.1. Cisco HDLC encapsulation
1.1.2. PPP encapsulation
1.1.3. Frame Relay encapsulation
1.1.4. Maximum transmission unit (MTU)
1.1.5. Cyclic redundancy check (CRC)
1.1.6. Keepalive timer
1.1.7. Frame Relay DLCI on point to point sub-interface
1.1.8. SONET Controller
1.1.9. POS channel

…and it begins (again)

Jeff Fry published on 2011-09-06 included in CCIE

Bette-Davis-Margo-Channing-All-About-Eve-150x150

Well I have decided to give one another shot, the CCIE SP lab. My last try was under the SP v2 track back in March, and after I did not make it I figured that would be it for me. Well, as my one friend puts it, these BHAG (Big Hairy Audacious Goals) are a driving force for us from time to time. The thought of giving up is not what people like us do, we perservere, learn from our mistakes, and go back at it. That, right there, is what drives many of us to achive the CCIE – and what is driving me to go for the CCIE SP v3 track now. My studies will start back up this week and blog posts on the topics will be sure to follow. Should be an interesting ride! You can look forward to seeing some interesting topics from me soon as well as the associated configs. Not quite sure how it will all work out, but as Bette Davis as Margo said in All About Eve – Fasten your seat belts. It’s going to be bumpy night! Here’s hoping for #2! [youtube=http://www.youtube.com/watch?v=XypVcv77WBU]

The Ultimate Cisco Live Attendee(s)

Jeff Fry published on 2011-08-16 included in Cisco Live

So who is the Ultimate Cisco Live Attendee? That is simple – not me nor my good friend, Tom – but Carole Warner Reece – as has been announced on the Newsroom site at Cisco (LINK)

To be honest, I have to agree with them on this one as Carole has been attending for over 10 years now, had had her CCIE for over 10 years, and works for a company that only continues to help the event with their quality employees. I want to congratulate here and say WELL DESERVED! She is more of a die hard fan then I am, heck she even wore a Star Trek shirt to the closing keynote with William Shatner, she has earned her title! It looks like Tom and I made a nice showing and got some great press from Cisco for our submissions. Me for my blog posts, and Tom for his uber nerdy video taken with his Cisco CIUS tablet. You can see his blog post on his feeling here. Oh, if you just want to see the video – here you go!

Cisco 3750 Stack Member Recovery

Jeff Fry published on 2011-08-15 included in IOS Problems

Interesting day today, that it was. Well, I guess I should say that the weekend was interesting as we had some bad weather – and just by some random chance we lost a CoreWAN router and a Cisco 3750 Stack member. So lets just say that I spent my morning recovering the WAN router by moving the circuits to another router and recovering a 3750 switch. Since moving WAN circuits around is no big deal, lets talk about recovering a Cisco 3750 stack member switch. I will assume you have identified the switch that is dead – no lights is a good indication – and have received your replacement switch from Cisco already. The first thing you should do is independently boot the new switch and check the IOS version and make sure that it is either the same or compatible. For me, I prefer to make sure they are the same before adding a switch to the stack as I never trust “compatible” version of switch code. If you have ever upgraded a 3750 stack, you know it can take some time for the stack to come back – over 10 minutes is not unheard of. So what do you do if you lose a switch in your stack, and have the right replacement? Amazingly enough, just swap it out and the stack will work as normal. Now, don’t we always wish life was that simple!

CatOS and IOS

Jeff Fry published on 2011-08-15 included in Data Center

Ahh, Catalyst OS – old skool Layer 2. There is a dwindling number of engineer who have seen this code, let alone have ever used this code and understand it. Since I am about to convert some of the CatOS switches at work to IOS, I figured I would share some of the basics and joys of CatOS with you. Ok, perhaps I am just reminiscing a bit here – but if this can help just one person, then all is good – right?
So, what is this thing called CatOS one might ask. Well, in short it is Cisco OS that is Layer 2 only; there are no routed interfaces, no IP addresses on interfaces (well, there is SC0) or IPs for VLANS – just L2 VLANS and Ports. When a Catalyst switch is running CatOS for Layer 2 it is called Hybrid mode – if the switch is running IOS for Layer 2 and Layer 3, it is called Native mode. CatOS dates back to 1993 when Cisco acquired Crescendo Communications in 1993 and the Catalyst line – its first foray into Switching – and because of the wide acceptance of XDi/CatOS, the OS has lived on for many years. As the Catalyst line moved forward from the 5000, to the 5500, and now the 6500 – CatOS has survived. It is only recently ( Dec 2010 ) that Cisco is no longer fixing and producing CatOS code, and CatOS code will finally go End-Of-Support in December of 2014.

DMVPN and Routing Protocols – CDP

Jeff Fry published on 2011-08-07 included in Cool Tech

This post will build off my last one, DMVPN, and here we will discuss the routing protocol options as well as each of their configurations. This is more of a Why? What? Eh? type of post – hence the picture. Here I will show how to use CDP for a routing protocol – yes, CDP.

Right from the Cisco kool-aid website: On-Demand Routing (ODR) is an enhancement to Cisco Discovery Protocol (CDP), a protocol used to discover other Cisco devices on either broadcast or non-broadcast media. With the help of CDP, it is possible to find the device type, the IP address, the Cisco IOS® version running on the neighbor Cisco device, the capabilities of the neighbor device, and so on. In Cisco IOS software release 11.2, ODR was added to CDP to advertise the connected IP prefix of a stub router via CDP. This feature takes an extra five bytes for each network or subnet, four bytes for the IP address, and one byte to advertise the subnet mask along with the IP. ODR is able to carry Variable Length Subnet Mask (VLSM) information.

In order to get this lab to work I had to tweak a few configs on the routers, namely I had to remove the 0/0 route I had pointing to the ISP and make it a more specific – 150.0.0.0/8 pointing to the “ISP” router as the next hop. With ODR only a default route (0/0) is passed from the hub to the spokes, so no other default route can exist.

Quick note: When I am posting the configurations for the sites I will only notate the routing protocol additions. If you need information on DMVPN configuration, see my previous post.