Snippet posts

Just as a quick note that over the next few months I will be posting a number of ‘snippet’ posts on various technologies and things that I have learned.

I have decided to call them snippet posts as they will not be technical posts on how said technologies work at a deep level, rather an overview of what they do and how to configure/use them on the Cisco platform.

I will also be trying to post some more technical articles on some things, these may be in the way of videos or longer postings but we shall cross those bridges when it comes to it…

Hope you all had a good holiday period and hope you all have a happy new year…

Snippet: BGP as a non-transit AS

In the example below we have three BGP autonomous systems (AS1, AS2 and AS3) each with one router in it.

In this example assume that AS3 is a customer of AS1 and AS2 and is multihoming their connection with the two upstream providers for redundancy if one of the providers was to fail.

In its default configuration BGP will re-advertise any routes advertised into the AS to all other peers, this means that if route x.x.x.x/24 was advertised to AS3 from AS2 then AS3 would advertise that route back out to AS1, this in most cases is a bad idea as your network could operate as a transit as (AS1 would use you to reach AS2) which could cause an increase in bandwidth use/costs.

In most cases you only want traffic destined for your network entering your network.

Luckily BGP offers a couple of really simple ways to stop your AS becoming a transit as: Continue reading

CCNP TSHOOT Complete… CCNP done!

Well I know it was only a week ago that I did the SWITCH but after initially looking over the TSHOOT material I started to think that this was definitely going to be the easiest of the three certifications.

In my day-job I do a lot of troubleshooting so my kind of mindset for the exam was already partially there, that coupled with the fact that it has been less than 6-months since I have done my ROUTE and SWITCH means that a lot of the things you learned whilst learning those technologies are still in place.

As the old saying goes, there is no rest for the wicked and I will be starting to head towards my next certification straight away. I am of two mindsets on which to do, CCIP or CCIE R&S. I will probably go for the CCIP as I think the technologies in that certification contribute a lot to the CCIE (tech such as MPLS, QoS, BGP etc.) so could kill two birds with one brick (what is it with me and old sayings today?…)

I am going to start the studies with QoS and hope to post a more technical series of posts on this subject over the next couple of weeks.

Thanks to all of those out there that supported me through the CCNP.


SWITCH – Passed

Well I am a little behind schedule (I said that I wanted to complete SWITCH by mid November) but hey at least I got it done in the right year (just!)

I took the CCNP SWITCH exam earlier today and passed by a decent amount, it was the first time I attempted the exam so that pleased me (and my wallet) as it took me a couple of times to pass the ROUTE exam.

At the moment I am intending to dive straight in and not take a break before the TSHOOT studies begin (actually I’ve already started).

I can foresee the TSHOOT being the easiest of the bunch as one of my main job duties in my day job is troubleshooting so tracing a problem through the various hops isn’t anything new to me (however having to traverse every single routing/transport protocol along the way is!).

If I was to be over-enthusiastic I would say that I will have the TSHOOT (and in turn the CCNP) in the bag within the month (as I have 12 days off as of next Tuesday :D) but failing that I am aiming at the middle of January.

Once that is complete then it is time to start toward the CCIP 🙂

Thanks for all the support along the way so far, it really helps.

Until then…. TTFN (ta ta for now for all you non Brits :P)