Network Analysis

At the moment I am researching which is the best tool to buy for an enterprise network in terms of discovering network performance and so I thought I would ask any readers of this blog for their recommendations.

First a bit of background I work in a support team in a large enterprise and we often get calls reporting the "network is slow". Now we have some tools that help us monitor the utilization of the links but they cannot show us the top talkers across the links. Our current tool set also does not allow us to see what protocols are being used across the link and we have no chance of being able to prove what application is causing the problem. It always turns out to be an application or patch deployment that causes the problem, however we usually have to let the users suffer from a "slow network" until the problem goes away. To me this is unacceptable service and I have started investigating products that can give us a bit more visibility into the network.

Ideally what I would like is an application that can pull NetFlow stats from the routers and via some sort of probe be able to investigate switched traffic. I would require the product to determine application responsiveness and ideally be able to build a baseline over time. We may also be consolidating data centres fairly soon and so discovering the relationships between servers would be a great bonus. As I want to make sure we migrate all the servers that talk heavily to each other as a package and we do not leave a server behind that then hammers the WAN link by talking to it's peers in the new data centre. Finally I would be interested in how the various products cope when WAN optimization is introduced into the network.

I have been looking at tools from MAZU, OpNet, NetScout and NetQoS but if anyone else has any recommendations I would be most grateful.

State of the Ferret 07/01/09

Well a belated Happy New Year to everyone. It has been a while since I have posted and that is because things have been pretty hectic with family commitments over the festive season as you can probably imagine. There were a few work commitments in there as well but studying did not go very well at all. I was trying to finish the OSPF sections in Narbik's workbook before Christmas, but I have only just got round to doing it now.

There comes a time in life where you have to face up to reality. My reality is that I am not even going to get close to being ready to do my lab in April. I have a second child on the way soon and I am only just beginning to remember how much work a new born child is. This time it will be especially challenging now that I have a toddler as well. With my wife going off on maternity leave imminently money is going to be tight and any free time I get will have to be spent focusing on doing overtime (providing it is not stopped) to make up for the shortfall in our finances. It will probably also pay to keep focused on the job a lot more in the current market, to try and ensure I do not join the massed ranks of the unemployed. So in short study time is going to be very scarce or non existent. This in turn has hit my motivation which is leading me to think I will never get round to doing the CCIE lab exam. I am trying to retain some of my knowledge by doing mini labs whenever I can but for now it looks like there will be no full scale practice labs for 6 to 8 months at least ouch :-(

On the good news front I did manage to get into the Everything IE beta but as it is confidential I cannot say anything about it at the moment.

Study Update 15/12/08

As you can probably tell from the lack of posts the studying has not been going very well as late. Work was previously taking it's toll with every piece of work being rushed in before the Christmas change freeze but now things are slowing down a bit in work due to the freeze and the fact that things generally slow down at Christmas. However the family commitments tend to pick up at this time of year so it does not look like I will get much more free time in fact family commitments tend to be even harsher than work commitments. To tell you the truth I have not been helping myself very much as I have been spending a lot of the time I should be reading the Cisco documentation browsing the web for presents or reading up on the current financial crisis and agonizing over whether it really is a good idea to buy that many presents this Christmas.

I have been plugging away at a few mini labs from Narbik's Advanced Technology Workbooks. (whoops I think I was so busy that I forgot to mention that I bought these in November just before the pound plummeted to much.) The workbooks are really good (I promise once I am through them I will compare them with the Internetwork Expert and the IPExpert workbooks) although I am taking my time getting through them. I am using Dynamips to run the workbooks so I have a topology that seems to work for the moment. I am still going through the OSPF section so I have not made great progress but I am repeating several of the mini labs to see if I can understand them a bit better.

The plan is to try and finish the OSPF section before my Christmas holiday in a weeks time and then start up again in the new year. Also I hope to get some time to setup the IPExpert Dynamips topology for my different machines, and if I get any free time over Christmas the plan it to at least hit the CCIE Command Memorizer to ensure I retain a bit of knowledge over the festive season.

In case I do not get a chance to post again best wishes to you and your families where ever you are in the world over the holiday season.

Commands: ispf

Looking through OSPF I came across a command I did not know about before. The command I came across was ispf, which stands for incremental shortest path first. The benefits of ispf can best be summed up from Cisco's own page on the topic.

OSPF uses Dijkstra's SPF algorithm to compute the shortest path tree (SPT). During the computation of the SPT, the shortest path to each node is discovered. The topology tree is used to populate the routing table with routes to IP networks. When changes to a Type-1 or Type-2 link-state advertisement (LSA) occur in an area, the entire SPT is recomputed. In many cases, the entire SPT need not be recomputed because most of the tree remains unchanged. Incremental SPF allows the system to recompute only the affected part of the tree. Recomputing only a portion of the tree rather than the entire tree results in faster OSPF convergence and saves CPU resources. Note that if the change to a Type-1 or Type-2 LSA occurs in the calculating router itself, then the full SPT is performed.

Incremental SPF is scheduled in the same way as the full SPF. Routers enabled with incremental SPF and routers not enabled with incremental SPF can function in the same internetwork.

Looks like quite a useful command to remember, so I will be adding it to my configs in future.

IPExpert Dynamips Configs

IPExpert have finally released their Dynamips configs. I have just downloaded mine from the members site so hopefully will get a chance to do a bit more labbing then I have been the last few weeks. It looks like they have 15 routers in the topology so it might be a bit difficult for me to get it all to run successfully on one PC but I will give it a go. Anyhow if you have not downloaded your files you can get them from your Internetwork Expert members page.

IPExpert Announcement Arrives

IPExpert's eagerly awaited announcement finally turned up in my inbox tonight. The main news I was interested in was the everything IE beta and the support for Dynamips. I have emailed IPExpert quite a few times in the past asking when they would introduce support for Dynamips and I was always knocked back saying it was not a Cisco supported product. So I was very happy when I saw that they were finally going to support Dynamips with their products. I was even happier when I read the announcement and found out that existing customers would get the .net topology file for free, click here for the official announcement. Oh and if you want to read the complete official announcement click here.

Update 27/11/08

Just a quick to post to say I am still around and alive. We just alive as someone decided it would be a good idea to knock me off my bike the other day. They did not even stop, they slowed down for a second and then sped off. Unfortunately the traffic lights further up the road changed just as I was running up to give them some serious abuse.

As well as being knocked off my real bike I have also been knocked off my CCIE bike over the last couple of weeks. I have been spending a lot of time doing up my house and DIY sucks up both your energy and your time. No sooner had I got all that work out the way and then my son was sick for a whole week and then to top it off I had to fly to one of our international locations for a couple of days.

So the studying has gone completely out the window. However in my foreign travels I did get to spend quite a bit of time working on the CCIE Command Memorizer and finding out how much stuff I had already forgotten. Anyhow here it to hoping I can get back on my CCIE bike next week and make some good progress in my studies.

CCIE Shorts 16/11/08

Work and my personal life have conspired to get on top of me the last few weeks and stop my blogging and studying. Anyhow I am still alive just and making a little bit of progress when ever I have some free time. Hopefully with the Christmas change freeze on the way work should be less of an issue in a few weeks. Anyhow to get my used to blogging again I thought I would post on some CCIE shorts that I wanted to get up but have not had the chance.

Firstly the CCIE Command Memorizer has been up dated. As well as the usual fixes the major new functionality is that you can finish your command with the Enter (Return) key rather than the Tab key. Apparently there was a lot of requests for this functionality which is why another update was rushed out so soon after the previous one. I never had any problems using the Tab key in fact I got used to it fairly quickly but I will let you know how I get on with the new version. I must admit I have not had much time to use the Command Memorizer as work has been very hectic and my normal routine was to spend 30 minutes a day at lunchtime using it. At the moment thought 30 minutes at lunch seems a distant memory so I have not had a chance to use it for at least 2 weeks. There has also been a subscription version of the Command Memorizer released, which Cisco Network Engineer has the details of.

I also noticed that IPExpert are having a Christmas sale and the BLS is back down to $999. The most exciting part of the sale for me though is that the rack rental sessions have been reduced in price. I still wish they would sort out some rack rental times that worked a bit better for Europe but at the price they are at the moment they are well worth investigating. Anyhow click here to check out the sale.

I have not had a chance to check out the latest Internetwork Expert news but hopefully I will get a chance in the next few days. I have been trying to justify the $1800 upgrade to the end-to-end program but with the value of the pound at the moment the chances of me being able to justify it diminish by the day.

Hopefully I will have a chance to do a study update in the next few days and get some good technical posts going but do not hold your breath at the moment :-)

Project 1:

I have been asked to help out on a little project for a friend and as I am not really up to date on all the wireless technologies out there I thought I would do a post to see if anyone else has any ideas.

Basically what I have been asked to do is setup is an outdoor back link to a primary satellite link. There will be a router probably Cisco as I believe they do ruggedised routers (any help on models greatly appreciated) which will be connected to a satellite link. The satellite link will be the primary connection used by a control station to connect to remote sensors in the field. What I need to do is provide a backup link for when the satellite link fails. The only time there should be any problems with the satellite link is when it is absolutely pouring with rain which tends to happen quite a lot on this island. I was looking into GPRS or 3G and at the moment GPRS is my favourite as Cisco have released a new GPRS card for their ISR routers. The initial plan is to connect to the remote sensors over the satellite link and then use the IP SLA service to check that the other end of the link is up. If the satellite link fails then I would want to fail over to the GRPS or 3G connection to make sure that the control station could still connect to the remote sensors.

So I have a couple of questions to anyone who know about these technologies or has setup similar systems. Firstly can you bond GRPS together to get a higher bandwidth connection with a Cisco router? Also how do GRPS and 3G perform in poor weather conditions? Any help out ruggedised routers and outdoor routing systems would be most appreciated.

Study Update 03/11/08

Okay so it has been a while since I posted a study update. As usual things have not been going to plan, I am still working a lot of hours which I need to do because of the overtime money I earn. This plays havoc with my study schedule because even if the change is taking place at 10:30 I have to get everything ready before that and so it completely disrupts my night of studying when ever I have to do a change.

I have however finally managed to finish the first week of the Internetwork Expert CoD I must have the record for taking the longest amount of time to finish the first week. I still have another week of the CoD to go which is probably going to take forever as well. I do find that some of the videos in both the Internetwork Expert and IPExpert CoD's are so long that I keep losing focus and I have to re-watch parts. I think that both IPExpert and Internetwork Expert really should think about cutting their videos down in to more manageable sections like CBT Nuggets do. (Internetwork Expert did announce they would be doing this in their CCIE 2.0 CoD's).

On the labbing front I have been working on some of the IPExpert Volume 1 labs which tend to kick my butt when I first try them. I do improve a lot when I have done at least one lab in a section but when I try the first lab in a new section/technology then I spend quite a bit of time stuck in the Proctor Guide. As I do not have a rack I have been using some Proctor Lab sessions to do the labs. The times the Proctor Lab sessions run are not the most convenient and I was getting up at 5 in the morning to work on the racks. However with the change of the clocks those sessions would now start at 4 in the morning my time which I can assure you is not very pleasant when it is cold and dark. I will have to look and see if the US clocks are going to change anytime soon or maybe Proctor Labs could think about changing some of the rack times to suit Europe and the rest of the world a little bit better.

I have not had much time for reading or spending on the Command Memorizer but I hope to do a bit more reading on BGP and get some more time on the Memorizer later this week. So the report at the moment is that I am treading water but I am still in the fight :-)