Suggested Listening

Sounds a little like something you’d see stuck in a library. . “Would you like to check the Suggested Listening section Sir?” …. “errr.. Is it in the Dungeon?” ūüôā

Quite aside from that, a new friend of mine asked me to put together 15 tracks of interest to check out and vice versa.

My selection is as follows:-

Magnet – Hold On
BodyRox – Yeah Yeah (D Ramirez Remix)
Aaron Jerome – Dancing Girl (feat. mozez)
Fink – If Only
Simian Mobile Disco – I Got This Down
Sweatshop Union – Better Days
Rae & Christian – Now I lay me down to sleep
Younger Brother – Sleepwalker (Part1)
The Dzihan & Kamien Orchestra live – Drophere (feat. M.Dita)
Aaron Jerome – Way of Life
Jimpster – Love Like This
Ozomatli – Ya Viene El Sol – The Beatle Bob remix
Benjamin Diamond – She’s Away
Mr. Sizef – Garmoniya Mirov
Bonobo – Recurring

Seriously – you should check this lot out, perhaps the title of this entry should be “Serious Listening” …

Love and Light

P

Advertisements

CCNP Track Exam Change

I’ve just this morning discovered that Cisco are changing the requirements to attain the CCNP qualification.

They are dropping the old BCMSN, BCSI, ONT and ISCW exams on July 31st 2010 and providing only 3 new exams to replace these old four.
They are SWITCH and ROUTE which are both available March 10th 2010 onwards and the TSHOOT exam which is available April 30th 2010.

Personally it’s not too much of an arse as you’re able to gain the certification with BCMSN, which I’ve just passed and the ROUTE and TSHOOT exams, or certain combinations thereof. See here for all options.

The ROUTE study guide is released Feb 10th 2010 and I hope that also makes it into digital format on Safari as I don’t fancy buying the big fat book in. The SWITCH and TSHOOT Exam Stugy guides are released on Feb 8th 2010, see here.

Good luck if you’re taking these new exams!

Peace
p

1 down, 3 to go

Yesterday I completed the BCMSN exam successfully, but damn, I was rusty!

I’d forgotten about all the prep to make myself comfortable I used to do, and did Cisco chuck the most monstrous question at me for question 1 of 58!? Damn!? I spent 15mins of my allocated 90mins on that first question. I really felt like a rabbit in the headlights! Obviously I recovered well and got my shit together but it really spun me out and gave me brainache.

Still, that said, I’m chuffed, and starting to get my shit together to prep for the BCSI which I’ll book when I feel like it’s all starting to go in.

Something else Cisco have chucked in there to help with the integrity of their qualifications which I wholly believe to be the best in the industry, is that the retake date has now increased to 180 days, so you’ve got 6 months before you can retake a failed exam! You REALLY don’t wanna muck em up now!

Peace

P

Converting a Cisco AP from LWAPP to Autonomous mode

Here’s a quick walk through to get a Cisco AP – in my case an 1130AG – from a controller based¬† LWAPP image back to the autonomous image so it can be used as a standalone AP again.

Retrieve the latest IOS image for your AP from Cisco.com
Retreive TFTPD for use as your TFTP server from here
You’ll need a PC with a static IP (10.0.0.1/24 for this example) to wire your AP straight into during the procedure, with the TFTP server running, all firewalls disabled and the IOS image available in the TFTP root.

Step 1: Make sure that the PC contains the access point image file (such as c1130-k9w7-tar.124-10b.JDA3.tar for an 1130 series access point) in the TFTP server folder and that the TFTP server is activated.

Step 2: Set the timeout value on the TFTP server to 30 seconds.

Step 3: On the PC where the TFTP server is located, perform these steps:

a. Disable any software firewall products, such as Windows firewall, ZoneAlarm firewall, McAffee firewall, or others.

b. Ensure all Windows files are visible. From Windows Explorer, click Tools > Folder Options > View; then uncheck the Hide extensions for known file types check box.

Step 4: Connect the PC to the access point using a Category 5 Ethernet cable.

Step 5: Disconnect power from the access point.

Step 6: Press and hold MODE while you reconnect power to the access point.

Step 7: Hold the MODE button until the status LED turns red (approximately 20 to 30 seconds) and then release.

Step 8: Enable LWAPP console CLI allow/disallow debugging

#debug lwapp con cli

Step 9: Enable LWAPP ignore internal reload debugging

#debug lwapp client no-reload

Step 10: Configure IP Address on the fast ethernet interface of the AP

#conf t
(config)#interface fa0
(config-if)#ip addr 10.0.0.2 255.255.255.0

Step 11: Download the image file from the TFTP server to the AP

#archive download-sw /overwrite tftp://10.0.0.1/c1130-k9w7-tar.124-10b.JDA3.tar

Step 12: Reload the unit once the image has been written and the process reports complete.

#reload.

You’ll now be running an autonomous image which you can work with.

Be Cool

P

Do switches dream of electric cars?

I’ve had a nice half day at home today after doing some OOH work last week on Citrix and SQL issues at work, during which I’ve been getting my Spanning Tree Protocol knowledge firmed up, ironed out, straight in my head coz I failed hard on that category a year ago when I last took my BCMSN exam.

One thing that caught me out was the spanning-tree port-priority and spanning-tree cost commands. Being that Spanning Tree is always looking for the lowest cost path back to the root bridge, muggins here thought that essentially these commands did one of the same thing on the non-root switch you were working on. Well, they do and they don’t, it’s where you apply these commands that counts.

In a simple topology where you have two swtiches, one root, and one non-root bridge for highlighting the example..default VLAN 1 and with two cables plugged into each switches Fa 13 and 14 ports as described here:-

Non-Root Fa 0/13 <-> Root Fa 0/13
Non-Root Fa 0/14 <-> Root Fa 0/14

Entering the command show spanning-tree from your non-root switch would result in the output as shown here for VLAN 1 (we’re using Rapid Spanning Tree)

Interface           Role Sts Cost      Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/13              Root FWD 19        128.13   P2p
Fa0/14              Altn BLK 19        128.14   P2p

This selection of the root port has been made by the non-root (downstream) switch because the Sender port of Fa 0/13 is lower than Fa 0/14 from the root bridge. Just to re-iterate, that 13 is linked to 13 and 14 to 14.
When referring to the Sender here, we’re remembering that configuration BPDUs are sent every two seconds from the root toward the downstream switches.

Lets just explore a little here, if I were to hook up the cables as such:-

Non-Root Fa 0/13 <-> Root Fa 0/15
Non-Root Fa 0/14 <-> Root Fa 0/14

the output of your show spanning-tree command from the non-root switch would look as such

Interface           Role Sts Cost      Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/13              Altn BLK 19        128.13   P2p
Fa0/14              Root FWD 19        128.14   P2p

So to summarise, you’ve changed the cabling of your Root switch and this has cause the root port to change on the Non-root switch because the Sender port-id was lower coming in on Fa 0/14.

So this is where the two interface commands spanning-tree port-priority and spanning-tree cost come into play.

2960SW1(config-if)#spanning-tree cost <1-200000000>  port path cost

using this command on the Non-root switch will change the cost, normally determined by the bandwidth of the link, so changing the cost of the link, here already stated as 19 as it’s a 100MB link, to 1 – a lower cost, will force Spanning-tree to choose that port as the root port as displayed here

Interface           Role Sts Cost      Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/13              Altn BLK 19        128.13   P2p
Fa0/14              Root FWD 1         128.14   P2p

See the Cost column is now one, and that is the new root port.
This command can be applied to the port for all VLANs using

2960SW1(config-if)#spanning-tree cost 1

or to a single VLAN on that port using the command as such

2960SW1(config-if)#spanning-tree vlan 66 cost 1

So that leaves the command spanning-tree port-priority doesn’t it! This command is used on the upstream switch and in this examples case, the root switch to influence downstream or non-root switches path decisions.

This time on your root or upstream switch, as an example you’d modify the higher interface’s properties as follows

3750SW1(config-if)#spanning-tree port-priority 112

the values accepted here are in increments of 16 away from the base value of 128, from 0 – 240. The value of 112 is the minimum you need to decrease the cost of the path using Fa 0/14 on the root switch. Again this can be done on a port or per-VLAN basis by changing the command to this

3750SW1(config-if)#spanning-tree vlan 66 port-priority 112

This configuration on the root switch would lead to this output on the non-root switch

Interface           Role Sts Cost      Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/13              Altn BLK 19        128.13   P2p
Fa0/14              Root FWD 19         128.14   P2p

See this time that the Cost is equal, but the decision has been made as a result of your upstream switches configuration to use the Fa 0/14 port as the root port instead of 13 which would naturally take precedence in a default configuration.

I hope this helps peeps de-mystify the STP path decisions somewhat.

On a completely separate buzz, I’ve passed through another stage of the selection process for the Smart-EV trial¬† in the South-East and London. It’ll be interesting, though the motor is lease hire and it’ll mean a fair amount of cash down the drain over a calendar year, fuel will for all intents and purposes be free and I’ll actually have a motor to go places in which is a monumental thing. I’ve been without four wheels for many years now and I recently sold my motorbike as it was simply not getting used.
I think next stop is test drive whilst they credit check me, so I’ll post my thoughts once I’ve had a go in it and let y’all know what I think!

Be Cool

P