Friday, 12th March 2010.

Posted on Friday, 21st December 2007 by sean

The 3750 (and it would appear, the 3560s, 4500s, and 6500s) have an integrated Time Domain Reflector which is used to test cables associated with a port.
http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_25_see/command/reference/cli3.html#wp2168243
Today I was troubleshooting a problem at a newly renovated remote office with an IP phone that would power up but not boot. After swapping cables and phones, [...]

Posted in Switching | Comments (1)

Posted on Thursday, 17th August 2006 by sean

I just got back from passing 642-811. Even though I ended up with a 962 the number of questions that I thought “I think that’s the right answer” would have made me think my score would have been lower (though as I go back and check, it looks like I was right on most)
Compared [...]

Posted in Reviews, Switching | Comments (1)

Posted on Tuesday, 11th July 2006 by sean

Implementation of multicast, at least for the purposes of the CCNP BCMSN exam, is pretty simple. Cisco has the Multicast Quick-Start Configuration Guide which goes over many different ways of doing it.
The exam seems to only care about Protocol Independent Multicast (PIM), which uses the router’s routing table to determine whether or not a [...]

Posted in Routing, Switching | Comments (0)

Posted on Monday, 10th July 2006 by sean

I labbed up some Multicast stuff a while ago and only now am sitting down to write it. I’d like to write BCMSN by the end of the month because I’m taking two weeks off at the beginning of August where I won’t be near the Internet (or my routers) too often.
What is multicast?
Multicast [...]

Posted in Switching | Comments (0)

Posted on Thursday, 8th June 2006 by sean

Just a note while I come up for air…
On most switches with a hardware priority queue (egress expedite queue) like the 3550, it’s statically assigned to queue 4 (on switches with 4 queues). Some switches like the 4500s let you switch the queue, but generally it’s on silicon so you’re stuck. No problem.
However, [...]

Posted in General, Switching | Comments (1)

Posted on Tuesday, 27th July 2004 by sean

The Spanning Tree Protocol (STP) exists to build a loop free path on layer two.
The exam outline has the following items related to STP:

Explain the operation and purpose of the Spanning-Tree Protocol (STP) on a switched network
Enable Spanning Tree on ports and VLANs
Configure Spanning Tree parameters including: port priority, VLAN priority, root bridge, BPDU guard, [...]

Posted in Switching | Comments (0)

Posted on Monday, 29th March 2004 by sean

In a pretty naked marketing attempt, the following objective appears on the outline:

Describe the features and operation of network analysis modules on Catalyst switches to improve network traffic management

Most of what I found on this is from the Network Analysis Module (NAM-1/NAM-2) page. The NAM 1/2 data sheets provide more information on what this [...]

Posted in Switching | Comments (0)

Posted on Wednesday, 17th March 2004 by sean

While I haven’t covered 802.1Q yet, I wanted to look at “QinQ“, allowing service providers to tunnel 802.1Q over their own managed ethernet network, which is likely running 802.1Q for customer separation.

Describe the features and operation of 802.1Q Tunneling (802.1QinQ) within a service provider network
Describe the operation and purpose of managed VLAN services

Packet Magazine ran [...]

Posted in Switching | Comments (2)

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