Ccies

Lab Strategy

I think being able to pass the lab has to do with more than just knowing stuff and being good at configuring whichever feature. You must have a strategy and be able to manage your time. Of course people are different which is why you should find out what works for you. But what ever you choose to do, make sure you stick to the plan.

Below is what I have decided to make my strategy. Also be sure to read at least the Battlefields Tactics Part I and II from Unleashing CCIE Routing and Switching v5.0.

PPP and PPPoE

PPP

PPP is a standards based protocol that offers authentication at L2. This is one of the main reasons why you’d use PPP to begin with. The other main reason is dynamic IP addressing. It was originally designed for dial-up connections.

Structured Troubleshooting

Having failed the CCIE R&S Lab Troubleshoot section, I decided to make a write-up on how troubleshooting should be approached. Not just for the lab, but in general.

We troubleshooting you are usually under a huge time pressure, because something is down. People can’t work and the business is loosing money. For me keeping calm and having a structured approach is key to becoming efficient in finding the root cause and fixing the issue causing the outage.

Spanning-Tree Protocol

I’ve always found STP a bit confusing. Partly because STP was designed in a time where L2 was a good way to do things. Nowadays building a network with heavy focus on L2 domains is obsolete IMHO. We do whatever we can to avoid having STP block links by using port-channels and routed links.

I will concentrate only on the flavors of STP that newer Catalyst switches support.

  • Legacy STP
      • Timers
      • Root Bridge Election
        •         <li>
          <a href="#Port_Roles">Port Roles</a>
        </li>
        <li>
          <a href="#Port_States">Port States</a>
        </li>
        <li>
          <a href="#Topology_Change">Topology Change</a><ul>
            <li>
              <a href="#Notify_The_Root">Notify The Root</a>
            </li>
            <li>
              <a href="#Notify_The_Network">Notify The Network</a>
            </li>
          </ul>
        </li>
        
        <li>
          <a href="#Traffic_Engineering">Traffic Engineering</a>
        </li>
        <li>
          <a href="#STP_On_The_Wire">STP On The Wire</a>
        </li>
        <li>
          <a href="#Optional_Features">Optional Features</a><ul>
            <li>
              <a href="#PortFast">PortFast</a>
            </li>
            <li>
              <a href="#BPDU_Guard">BPDU Guard</a>
            </li>
            <li>
              <a href="#BPDU_Filter">BPDU Filter</a>
            </li>
            <li>
              <a href="#Loopguard">Loopguard</a>
            </li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</li>

<li>
  <a href="#RSTPMST">RSTP/MST</a>
</li>

Legacy STP

Aka. PVST+. The default mode running on most Catalyst switches today. It is a timer driven flavor of STP and therefore slow to converge.