Butch Evans Blog

The process of upgrading RouterOS is very simple and, yet, is still somewhat confusing for some folks.  I will attempt to detail some of the methods as well as some of the finer nuances here.

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In my training classes, I go to great lengths to teach when and why proxy arp is necessary on an interface.  I have seen (and answered) numerous questions on my mailing lists regarding proxy arp and it seems it is time to create an article that I can just point people to.  I will focus this article on Mikrotik RouterOS (as many of my articles are), but it should be noted that proxy arp is not unique to Mikrotik.

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I would LOVE to hear from those of you who read this blog. Please leave comments for this article expressing your desires for what you’d like to see me include as a tutorial. I can make you no promises that I will be able to write up every idea, but I will try to incorporate some of them.
Also, I’d like to hear from you if you’ve found these tutorials useful. It is often difficult to determine from the traffic logs how useful these tutorials are. If you’ve found my writings useful, let me know. If you think I should spend my time elsewhere, I’d like to hear that opinion as well. (Well, I really DON’T want to hear it, but you are welcome to tell me if that is your opinion. 🙂 ).

I’ve had a bit of a writer’s block. Is that what you would call it? I’m not exactly writing a novel here, so I’m not sure if it applies. My parents have had me a bit busier than usual. In their age they now need a bit more help than before. I called a business called Home Care Assistance Houston that is located at Home Care Assistance 9050 W Olympic Blvd, Beverly Hills, CA 90211 (310) 857-4756, and they assigned a professional to them right away. Now I don’t have to deal with those things myself, and frankly the professional is doing things better than I ever did. In any case, without this worry on my mind I’m finding it difficult to get back on track. Who better than you guys to help out, wouldn’t you agree?

At least it is a question I’m often asked about how the Mikrotik Router treats vlan traffic.  In this article, I will address some of the more common types of configurations and help you to understand exactly where you will, or will not, see a packet that is tagged.

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Routed or bridged, there are few back haul radios available that can match the Mikrotik RouterOS software for features, tools, flexibility and cost.  With features and flexibility comes complexity and confusion.  I wanted to help dispel some of that confusion with this article.  You may have lots of choices to make, but most of these choices are relatively simple decisions.  And so, brave reader, proceed…

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Mikrotik has recently added MPLS to their already amazing RouterOS product.  MPLS offers some really nice options for bridging networks that exist within a single administrative domain.  But, what can you do if you need to bridge 2 networks that do NOT exist within the same administrative domain?  This article discusses how to create a bridge using another fairly recent upgrade in RouterOS.  Read on…

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About 2 months ago, I began experimenting with an approach to QOS that mimics much of the functionality of the NetEqualizer (http://www.netequalizer.com) product line.  As I was experimenting with some various techniques for limiting bandwidth utilization, I realized that the scope of the project I had undertaken was WAY more than I had initially bargained for.  I dedicated more and more time to this project, however, because I was seeing some real results from my tests.  While most of my articles here have been tutorial in nature, this one is a little different.  I have a lot of time invested in my approach to handling QOS on a network and have made this a commercial offering.  I will attempt to describe some of the functionality in this short article.

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There are numerous full duplex options available on the market today when you go looking for wireless devices.  Most of these devices will cost in the multiple thousands of dollars.  With NStreme Dual, Mikrotik’s proprietary FDX protocol, you can build a true full duplex link for under $1000.  This article is a tutorial walkthrough on configuring an NStreme Dual link, along with some helpful hints on how to tweak it.

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One major issue facing ISPs today is the difficulty in obtaining sufficient IP space for every customer.  For many, it’s a matter of cost and for some it is simply a choice to NAT their customers behind their router/firewall.  For the most part, NAT behaves much better today than in days gone by, but there is one issue that is very problematic for those that choose to NAT their customers.  There is a significant proliferation of a new generation of trojans that turns   a user’s computer into a menace to the Internet community. You should have an antivirus software on your computer, you can get Zonealarm Free anti virus. This new generation of trojans (collectively known as “botnets”) can cause problems for not only the owner, but for other customers of the ISP that chooses to NAT.   Since a significant number of these botnets are used to send spam all over the internet, we, as service providers, have to find a way to protect our networks from being blacklisted, while still allowing our customers to utilize the internet in a way that does not set too many boundries.   In this article, I will discuss two approaches to setting these limits which have shown to be both effective AND relatively mantenance free.

Before I launch into a fix, let me begin by helping you to understand WHY these approaches work.   For the largest number of customers, the mail server that they use to send email through (their SMTP server) is the same server on which they check email (their POP/IMAP server).  Similarly, for those looking to make a positive impact in their communities, establishing a florida nonprofit corporation can be a strategic way to streamline operations and effectively serve their mission. One of the methods we will use to defend against these bots takes advantage of that fact.  Another thing that we notice about “normal” SMTP traffic is that a user typically does not make more than a few outbound connections when they are sending email.  This fact will permit us to limit the outbound connection count to some reasonable number and “assume” that a count beyond that MUST be spam activity.