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Posts tagged ‘cisco’

3
Mar

IPv6: Cisco IOS

Addressing. Routing. DHCP. EIGRP. HSRP. Mobility. After consuming Cisco’s 706-page IOS IPv6 Configuration Guide, these are just a few of the areas we’re processing as the deployment plan starts coming together. If you’re running something other than Cisco, some of the commands below, and of course EIGRP, may not directly apply, but perhaps you can abstract the concepts and use them in your own network.

Here’s a rundown of the IOS commands we’ll be utilizing as we begin to implement:

  • ipv6 address: (Interface) Apply to VLAN interfaces, routing interfaces, etc (i.e. vlan20, g1/10, g2/0/23)
  • ipv6 general-prefix: (Global) Specifies the prefix of your IPv6 address space (i.e. 2001:d8:91B5::/48)
  • ipv6 unicast-routing: (Global) Enables IPv6 routing on the switch/router
  • ip name-server: (Global) Not specific to IPv4 or v6, but necessary to add IPv6 name server addresses
  • ipv6 dhcp relay destination: (Interface) Configure on all interfaces that need DHCP relaying
  • ipv6 eigrp: (Interface) Unlike IPv4, EIGRP is interface-specific (no “network” statements); apply to routing interfaces
  • ipv6 router eigrp: (Global) Creates the EIGRP router process on the switch
  • ipv6 hello-interval eigrp: (Interface) Configured on interfaces using EIGRP to set the frequency of hello packets to adjacent routers
  • ipv6 hold-time eigrp: (Interface) Configured on interfaces using EIGRP to tell neighbors how long the sender is valid

Coming next: a consolidated IPv6 deployment plan, derived from NIST Guidelines for the Secure Deployment of IPv6

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By Chris Gurley, MCSE, CCNA
Last updated: March 3, 2011

18
Feb

VCE: Virtual Computing Environment

Are you familiar with VCE? If not, add it to your IT acronym dictionary, but it’ll be something you hear more about in the future if virtualization, shared storage, converged networks, and/or server infrastructure are in your purview. VCE stands for “Virtual Computing Environment” and is a consortium of Cisco, EMC, VMware, and Intel (funny…if you take three of those initials, you get V-C-E). The goal and objective, which they seem to be realizing, is to deliver a “datacenter in a box” (or multiple boxes, if your environment is large), and in a lot of ways, I think they have something going…

The highlights for quick consumption:

  • a VCE Vblock is an encapsulated, manufactured product (SAN, servers, network fully assembled at the VCE factory)
  • a Vblock solution is designed to be sized to your environment based on profiling of 200,000+ virtual environments
  • one of the top VCE marketed advantages is a single support contact and services center for all components (no more finger pointing)
  • because a Vblock follows “recipes” for performance needs and profiles, upgrades also come/require fixed increments
  • Cisco UCS blade increments are in “packs” of four (4) blades; EMC disks come in five (5) RAID group “packs”
  • Vblock-0 is good for 300-800 VMs; Vblock-1 is for 800-3000 VMs; Vblock-2 supports 3000-6000 VMs
  • when crossing the VM threshold for a Vblock size, Vblocks can be aggregated

Those are the general facts. So what does all that mean for interested organizations? Is it a good fit for you? Here are some takeaways I drew from the points above as well as the rest of the briefing by our VCE, EMC, and Cisco reps… Read moreRead more

14
Feb

Coming Attractions: Service Manager & IPv6

On this fine evening, we wanted to share with you a little preview of coming attractions, which will hopefully appear in future posts. Two of our projects revolve around Microsoft System Center Service Manager and IPv6 (separate endeavors). Both of these hold good promise for our organization and where we go with each may help you as well.

Through the years, we’ve used a couple different help desk and change management tools–Track-It! and Alloy Navigator–and in each, we’ve run into issues and shortcomings. Track-It! was fine as a ticketing system, but provided very little correlation (if any), no audit trail, and sparse asset management. Alloy is a step in the right direction with a pretty comprehensive set of features, ranging from Purchase Orders to Incident and Change Management to Asset tracking, but the application and system itself are fraught with bugs, counter-intuitive processes, etc. In other words, lots of ongoing work which is worthy of many tickets itself.

So we’re venturing into Microsoft’s Service Manager territory and are very interested in the integration with the rest of the System Center suite (Configuration Manager and Operations Manager), as well as Active Directory. We’re also checking out Provance IT Asset Management, a management pack for SM, which enhances the product and provides an otherwise absent financial piece. Looking good so far!

On the networking side, we’ve been in the R&D phase with IPv6 (Internet Protocol version 6) for a few months now since receiving our own /48 block of addresses from ARIN. The documentation online is a bit sparse and mostly targeted to either consumers (Teredo) or ISPs, but we’re finding some nuggets in the digging.  Some good resources thus far are:

IPv6 is quite the undertaking, but as we work to roll it out in our organization, we’ll be sharing info to help in yours.

27
Jan

Upgrading a Cisco MDS 9500

We recently performed some upgrade our Cisco MDS 9509 and thought we’d share the steps with you. You’re welcome to hop on Cisco.com as well and grab the user guide, but if you’re running a 9500 with redundant Sup-2’s, this should be all you need to hop between SAN-OS 3.x versions and all the way up to NX-OS 5.x… Read moreRead more

6
Jan

VMware & Link-State Tracking

If you’re running a VMware vSphere cluster on a two-tier (or greater) Cisco network, you might be in a situation like I was. You see, we built in redundancy when we planned our core and access switches, but the design had one significant flaw (see the simplified diagram to the right). Pretend all of those lines are redundant paths. Looks good so far, right? If CoreA goes down, ESX(i) can still send traffic up through AccessB to CoreB. The reverse applies if -B is down, and likewise for either of the Access- switches.

The catch comes for VMs on ESX(i) when one of the Core- switches goes down. ESX(i) balances VMs across the ports in the Virtual Machine port group(s). If a port goes down, it will smartly move the VM(s) to another port that is up. If an “upstream” hop like CoreB goes down, though, ESX(i) doesn’t know about that event, so it keeps its VMs in place, oblivious to the fact that the VMs on AccessB ports are as good as dead to the world. [Enter Link-State Tracking] Read moreRead more