First off I’d like to say that this is just a minor issue, more relating for routers versus switch, I’m still a lot happier at how Cisco implements config and features as opposed to most if not all of their competitors…

At a customer I’ve recently had to commit a grave operational sin; to connect a small switch at the end of a floor patch. These things are normally operational nightmares as they have a tendency to quickly bring an entire LAN environment down to its knees when such a ‘switch’ is connected to the network twice. Always by accident but having management kick you for something someone else did is not anyone’s idea of fun. I won’t go into the underlying principles here as I’m assuming most who frequent my blog will know about broadcast storms, their causes and the tools and solutions available to mitigate the risks.

Our justification to operations was that we wanted a few more local LAN ports to test VoIP devices on than we had available through floor patches. As such I reasoned with Operations that this was a calculated choice to segregate our testing from the rest of the LAN but still make it as realistic as possible. Using the means available meant that I had to make do with a Cisco 1801. Single routed and 8 switched interfaces. Think of it as a router with one Ethernet interface and an 8 port HWIC-ESW nailed to it. Didn’t need the ATM or WiFi it has.

So I set out, disabling IP routing, admin down all non-Ethernet ports. set up the vlan database -old style, remember?-; I did not want this baby to participate in VTP, in fact I don’t think it even can! It’s limited to 8 vlans. Pulled two cables to it. One switched port as trunked with some data and voice vlans and configured the routed interface for management access.

All sweet and dandy, tested the BPDU-guard functionality prior to installation by connecting an access-port to the LAN. Clunk! it went down as desired, result I thought… Then when installing the LAN wouldn’t bring up the LAN port. Doh! I’d missed that the 1801 doesn’t send BPDU’s until a VLAN becomes active. I’d checked if spanning-tree was operational, and it wasn’t until I brought an interface up. So I disabled STP for all vlans in the VLAN database. Now my laptop received an IP address and the data VLANs all worked.

So, time to connect a Mitel phone. No dice, it received it’s first DHCP response with VLAn information, then it would just sit ennuncing it was waiting for a DHCP response. Dang, I’d configured the voice vlan so why did the switch not detect the phone, enable trunking so that the phone could send it’s DHCP request on the voice VLAN?

It was only when I started reading up on HWIC-ESW voice-VLAN config I noticed that Cisco hasn’t implemented the auto enable of dot1q trunking when a phone is detected… The solution is to add two lines of code; “switchport truck native vlan xyz” and “switchport mode trunk”. The crux is that this platform is at heart a router, not a native switch…

Cisco documentation

Categories: Networking, VoIP, Work
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Long live Social http://alexking.org/blog/2012/05/22/social-2-5

Testing automatic posting to Twitter and Facebook from my blog, sorry if you consider this spam.

Tags: facebook,twitter,wordpress
Categories: CCIE R&S
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This one has been coming for a while… Last time I went for my CCIE was Q3 2007 and it’s been pretty quiet here since. In the mean time I’ve moved country, changed jobs and moved again, though not as far. So how is my CCIE doing? Well to be honest, it’s not.

You see, I came from a sponsored certification track -which incidentally I forged with my employer at the time- and thus had to sort out a transfer sum from my new employer. No problem for the Dutch employment market, at least at the time. But here in the UK I had no such luck, suffice to say that financially it was not a good idea to move country. My new employer expressed that they would be happy to support attaining CCIE status. Little did I know that we had completely different concepts of ‘support’.

Loving a new challenge I quickly settled into my new position, only to find two years had gone before the question of attaining CCIE popped up again. No wonder really when you have a 100% billable target and there’s plenty of over time involved in the projects at hand. Then when things settled down and I moved to another customer I only found myself further and further away from technology. Yes I still design and have a consulting role but I’m in no way challenged and kept on my toes protocol wise. It took a few technical interviews to fully realise the impact of this.

Which brought me to this point: Either, I work and retrain myself towards CCIE in my own time, hope my employer will pay for the lab and favour me with a week off for full-time study. Or do I let go of the desire to attain CCIE and trust that there will be employers out there who are smart enough not to be blind sided by a the highly praised numbers of my peers.

In conclusion I refuse to ask my family for a long and hefty sacrifice once again, been there done that. I’m now one kid and two cancers (promisestoday.com/@maizymoo tweet) further and value my own time more than my career, if this means UK employers don’t like me any more than so be it. I know what I’m capable of, just wish I was better at convincing prospective employers…

Tags: CCIE,cisco
Categories: CCIE R&S, Main blog, Work
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Recently I’ve been doing more on Alcatel as I’m working in O2′s test-bed down in Slough, slaving away at testing aspects of their new LLU broadband core and new BT 21CN wholesale connectivity. Although I’ve not been able to write a lot in recent years due working for an integrator rather than an ISP; I’m mostly not allowed or it’s unwise for me to divulge what I’m working on…

However, it’s common knowledge that many providers use Alcatel and they seem to do pretty well in the ‘booming’ broadband market. Hence I thought I’d share a little snippet of an annoyance I recently encountered.

When using an Alcatel 7210 to sniff traffic and interconnect different media; 1Gbps copper and 10Gbps fibre. I found that sniffing is counter intuitive to people only trained on Cisco. A few pointers:

1. Port mirror destinations are defined in configuration
2. Port mirror sources are set through debug commands
3. When mirroring VPLS ports (I needed an e-pipe/Layer-2 tunnel) I found that egress sources did not work, only ingress did and only one ingress port can be set per mirror session. It did not matter if I use the port or the SAP as source.

I was left to sniff in two places to capture both up- & down-stream traffic. YMMV as a 7750 will be different, but I don’t have one available to me to test on…

Commands used:

#--------------------------------------------------
echo "Mirror Configuration"
#--------------------------------------------------
  mirror
    mirror-dest 4 create
      sap 1/1/4 create
      exit
      no shutdown
    exit
    mirror-dest 11 create
      sap 1/1/11 create
      exit
      no shutdown
    exit
  exit

And the debug command:

*A:<hostname># debug mirror-source 4 port ?
- no port ...
- port <port-id> egress ingress
- port <port-id> egress
- port <port-id> ingress
- port lag ...

*A:<hostname># debug mirror-source 4 sap ?
- no sap <sap-id> [ingress]
- sap <sap-id> {[ingress] }

As can be seen above capturing by SAP is only supported at ingress. Using port and SAP yielded the same result, only ingress packets were ever sent to the destination port. Despite show mirror stating both Egr & Ing.

*A:<hostname># show mirror mirror-dest 11

===============================================================================
Mirror Service
===============================================================================
Service Id       : 11                   Type          : Ether
Description      : (Not Specified)
Admin State      : Up                   Oper State    : Up
Forwarding Class : be                   Remote Sources: No
Slice            : 0
Destination SAP  : 1/1/11               Egr QoS Policy: 1

-------------------------------------------------------------------------------
Local Sources
-------------------------------------------------------------------------------
Admin State      : Up

-Port                                   1/1/26                          Egr Ing
===============================================================================

Tags: 7210,Alcatel,port mirroring,port span
Categories: Networking, Work
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Doing a network upgrade of 28 sites, 60 services and roughly 160 old devices to just 60 devices. Python has become my friend for reading configs, creating csv files and verification. Will be posting my scripts later. I’m sure there are clever people out there who can tell me where I went wrong or what I could be doing better. However time fails me to post them right now.

Tags: cisco,linkedin,migration,nortel,python
Categories: Work
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Not posted much recently, it’s time to add some more meat…

Last week I passed the F5 BIG-IP LTM v9.0 essentials exam. Was easier than I thought, however tomorrow I may be humbled further as I go for the advanced version of the F5 BIG-IP LTM v9.0 test. Studying with the training books from 4 days worth of training but without further hands on is not what I call fun. Admittedly it’s a lot easier than CCIE so what really am I moaning about. I suppose it the fact that I’m not studying for my next lab…

Tags: exam,F5
Categories: Main blog, Work
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Ouch. Humility is a painful process…

I’ve just been taught a lesson in humility and authorship. My post about Cisco’s NTP authentication implementation received a comment from a certain Frank. I’ve added my comment and need to verify my statment as soon as I can manage to get some hands-on in a lab again (not got Dynamips set-up yet)…

Categories: CCIE R&S
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Finally some news to write. Not that I haven’t been busy but just not with CCIE. Have had too much on my mind and finally I can write about it.

Today I’ve resigned from my position at Easynet and signed with nscglobal as a Consultant. First thing while writing here is to thank Easynet for the time there, the opportunities and trust given to me. Despite moving my desk from Rotterdam to Amsterdam within six months of employment, I have thoroughly enjoyed working for Easynet. Seeing it mature from a internationally fragmented company into an upcoming global enterprise player has been both challenging and inspiring.

For those who don’t know nscglobal, they’re a UK integrator and I’ll be working in one of their London offices. This means moving from The Netherlands to the United Kingdom and we’ll be doing so physically in January. We’re looking for a rental house for multiple reasons but for this site the relevant one is my CCIE. Once in the UK I need to start focussing on my CCIE again and I hope to be able to do so with the support of some of the CCIE’s nscglobal has. So be ready for some new CCIE updates starting January.

Till then I’ll probably blog about whatever technology comes my way during the move. For example the UK mobile operator 3 has an offer with free Skype calls so I might be looking into UMTS coverage in London, Hitchin and the rest of the extended North of London. Plus I’ll be looking for a hosting location for my two servers, offers are welcome. Offers for dedicated hosting too, might help the uptime of things… My VoIP setup will have to change as well, only slightly as I’ll only be adding an FXO port at home.

Anyway just keep reading and you’ll find out, the great thing is that I don’t have to keep silent any more about what is going on and that we’re looking forward to new things.

Categories: Main blog, Work
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*Sigh* Took me an hour or two to figure this one out. Cacti now does a ping before actually polling a device for stats. I’m running a small cacti site which had been neglected for a long time. After updating cacti and cleaning up some mess I was confused why one router did get polled and the other’s graphs remained a dumb “nan”.

I debugged and pinged, even installed hping3 to do UDP pings. I don’t want to run cacti as root, especially not on a vhost. So the UDP ping had to work. The pings arrived but still no replies.

Getting sidetracked I noticed that the one router that did work was being hit by SSH login attempts and it’s cpu was spiking. An ACL took care of the break-in attempts but then I noticed that directed broadcasts were made to my server’s segment. So I nailed that down plus proxy-arps when I noticed that the router which had worked before now was causing errors in Cacti as well.

Tracking back I noticed that the UDP ping ‘replies’ were unreachables rather than ICMP replies (doh, how obvious!) . I enabled IP unreachables on both routers again and I was done. It’s amazing how blind one can be at times to the blatantly obvious…

Categories: Main blog, Networking, Work
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Only just noticed but in effect since September 7th. The CCIE lab exam has gone up from $1250 to $1400, which results in $1694,- / €1199,30 including the 21% VAT for the Brussels lab location.

Even though it’s a 12% price increase it’s been 8 years since the previous increase. It’s been argued on Groupstudy that a 2% annual increase is not bad as it’s relatively on par with the inflation we’ve seen over the last 8 years. Never the less for those of us forced to pay for our own labs it’s a bitter pill to take.

Also note that all exams from CCNA to the CCIE written and lab have increased in price.

Categories: CCIE R&S, Main blog
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A recent question prompted this post. I’ve noticed that my site is getting more popular, despite my silence over the past weeks. I hope to propperly break the silence soon. All I can say now is that I’m busy working out an action plan towards my next lab attempt. By no means am I giving up!

Since my last post I’ve been very busy with work related issues and as such have not had the time or the right frame of mind to study. Please bear with me as I work to get back into the game. Feel free to comment on my previous posts, or this one if you like. It really helps me to know that other find this stuff useful.

Categories: CCIE R&S, Main blog, Work
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Since 12.3 (T?), static routes pointing to interfaces will be advertised by RIP and EIGRP as these static subnets are assumed to be part of the interfaces on which RIP and/or EIGRP is activated.

ip route prefix mask {ip-address | interface-type interface-number [ip-address]} [dhcp] [distance] [name next-hop-name] [permanent | track number] [tag tag]

Show me more… »

Categories: CCIE R&S, Main blog, Networking, Work
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Eek, Cisco keeps tabs on page hits when checking available lab seats. I set up firefox to automatically reload the page which works fine but resulted in me being locked out. Luckily only for a day but at 28 days before my ideal lab date this is not funny.

The following advice to all who’re desperate for a lab date: Be persistent but do not over do it.

ERROR: The ‘Available Lab Seats’ activity limit for the candidate has been exceeded for today. Please try again tomorrow.

Categories: CCIE R&S, Main blog
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Wow, I managed to spot and book the 2nd of October instead of my February 7th seat. Hopefully I’ll manage to swap this day for September 14th with someone from Vietnam. Poor guy that is a long way to come for a lab… But as you can see from my previous post swapping seats is a risky business.

[edit, 17 Aug 2007] I’ve managed to move to September 28th and I’ll stick with it for now. There’s enough to keep me busy till then, may circumstantially even have to move my date back. I’ll be diving back into the books/lab next week, too much social stuff going on this week.

[edit, 10 Sep 2007] Sadly I have cancelled my September 28th seat. There’s just too much going on right now to be able to concentrate, let alone to have enough time to commit to studying. I’m hoping I’ll ba able to move my Feb 19th date forward but for now it would be wise to keep the February date, at least until some things settle down.

Categories: CCIE R&S, Main blog
3 Comments »

As many people have found it’s rather hard to book a lab seat these days. All locations are fully booked. The occasional cancellations are snapped up in minutes.

I did manage to book a seat but it’s one of the seats that became available last Saturday, Cisco gives seats out 6 months ahead of time. They are snapped up within hours if not minutes. Many people just book anywhere in the hope they can swap later on, or figure out how to pay for the travel. Mails about swapping lab seats are becoming more and more frequent on Groupstudy.

I must admit that I’ve joined the ranks here. I’m looking for a seat on Sept 10th. Need to call Cisco today, hoping to be able to safely swap seats with someone who is willing to swap Sept 14th for my day in Feb. So my advice to anyone planning to take their lab in the next year: Plan your lab carefully.

[edit, 15 Aug 2007] Well I called Cisco (see this link) and as expected they refuse to swap lab dates. No manual database work will be done. When I argued that seats are booked within minutes after becoming available, their advise was to swap seats during off peak hours. My goodness even I considered flying out to Sao Paulo, this is a global struggle for CCIE lab seats. There are no off peak hours!

So for those planning to swap dates. My advice is get on the phone, MSN, IRC or whatever other low delay medium (this means no e-mail) and make sure you pick each others dropped seats up asap. Sadly there is no safe was of swapping seats.

Categories: CCIE R&S, Main blog
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