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  • My Thumb Drive 3

    More tools.

    HFS(HTTP FIle Server)– A quick program that hosts files via http.  Even if most common ports are blocked, you can almost always hit port 80.  So just fire this guy up, add a folder or individual files and boom.  It has soooo many options beyond just that, but that’s all I ever use it for.  I use it most often when dealing with unity express.  To transfer most files you have to use http, and this does the job perfectly.

    Filemon– Another Sysinternals special.  Monitor what files are in use by which applications.

    Omziff – This is a file encryption tool, file splitter, file shredder and hash generator.

    Depends.exe – M$ dependency walker.  You can specify a DLL and it will tell you all other DLLs that it references.  It also gives you insight into these files.

    Autologon– Sysinternals prog that sets one of the windows accounts to autologon on boot.

    WinXP Virtual CD – This is a little prog that was released by M$.  It allows you to mount an ISO as a virtual cd-rom.

    Tftpd32 – This is one of my favorite apps.  This is a great tftp server, dhcp server, tftp client, syslog server and sntp server.  I’ve used this little app countless times!  This is a must have for every USB drive.

    Text Crawler – This is another great prog.  Whenever you have a pile of files and you are looking for specific words, this is invaluable.  You can match using standard find strings or regex expressions.  I’ve used it to crawl database exports.  I’ve used it to crawl countless opensource packages.  It also has a regex tester, which is really convenient.

  • What do I use for my video tutorials?

    I use Wink!  It basically does screen shots and allows you to add buttons and text boxes.  They also allow you to record audio to go along with the presentation, but I haven’t tested it yet.  I’ve been using Wink for years.  As is most of the software I use, it is free!

  • Bind 9 – “refused notify from non-master”

    I was adding a new slave DNS server the other day on bind 9.3 and I was getting this error “refused notify from non-master”.  It seems that if you are using bind 9.3 it tries to send a notify to itself even if it is a slave.  In the options section of named.conf you need to add an allow-notify for it’s own IP.  Substitute 192.168.0.1 for your server’s IP.

    options {
    //otherstuff
    allow-notify {192.168.0.1;};
    };

  • DNS A Record Change by Tracking Servers

    Here’s the scenario:  You have a main site(MS), and a DR site(DR).   You have addressing 1.1.1.0/24 at the MS and addressing 2.2.2.0/24 at the DR site.  You have several web-servers at the MS that replicate regularly over to the DR site.  You want to fail over to the DR servers in the event of a meltdown at the MS.

    1. You could peer via BGP at the DR site and use prepending or conditional BGP to advertise the 1.1.1.0 subnet.  The customer says this isn’t an option.
    2. You could use a load-balancer such as an F5, Barracuda or a Cisco LocalDirector.  This in undesirable because the DR site has higher bandwidth costs so the numbers won’t add up.
    3. You could set the TTL on your DNS records to 60 seconds and in the event of a failure, change the A records over to your DR subnet.  This would require human intervention, though it would work perfectly well.
    4. Distributed Director.  Wes, a friend of mine turned me onto this.  Cisco put out a small IOS app a good while back called Distributed Director.  What this allows you to do is be authoritative for a DNS zone or record.  You in essence turn your router into a DNS server.  Why would you want to do this?  Because it allows you to add multiple servers to the pool for a single DNS record.  You can set the percentage of requests to go to one server or another.  You can also do tracking of a sort.  You can say, attempt to establish a connection to port 80 on a server to ensure the web server is running.  You can also give it a url and see if it responds.  This is a a pretty solid method, but the client doesn’t want to configure and maintain equipment.
    5. You could use a tracked DNS service.  A tracked DNS service is one that uses UDP, TCP, ICMP,  HTTP individually or in combination to track server status.  For example:  at my MS I track my webserver by issuing an HTTP request every two minutes.  I parse this HTTP request looking for specific keywords like “Company X”.  If I find those key words I do nothing.  If my server doesn’t respond properly, I start checking a list of alternate servers, namely my DR site server.  My DR server responds properly, so I change the A record over to the DR IP.  Within 60 seconds, all requests will start pointing over to my DR site, and I didn’t have to do anything, it was all automatic.

    As you can tell, The 5th option was the suggestion to the customer.  The feature seems like it would be a popular one, though there only seem to be a handful of providers out there.  Two in particular seemed interesting: dnsmadeeasy and ultradns.

    DNSMadeEasyis the cheaper of the two.  They offer a business package that includes 25 domains and 3 free “trackers.”  Tracker is the service that monitors the servers for failover.  You can add additional trackers for $5 and additional domains for $.75.

    UltraDNSis the pricey option, but for a reason.  They have far more bells and whistles: load-balancing by region, better server density throughout the world.  These are the guys that do DNS for facebook and amazon.

    I’m thinking of working on an Open-Source version, and here it is!

  • My Thumb Drive 2 – Electric Boogaloo

    More of my tools.

    Quick Mailer– I use this to test sending emails through open relays and the like.  You can kick out a quick email from some ridiculous source to your coworkers 😉

    Putty– I used to use tutty because it added serial support, but now putty itself does serial support.  This allows you to telnet/ssh/serial into any of your devices.  I use this for all my connections, router or server.

    Proccess explorer– Another sysinternals prog.  This allows you to find some hidden running progs and smite them…at least, that’s what I use it for.

    mstsc.exe – This is the windows remote desktop client.  I keep this on my thumb drive just in case.  I have hit a few machines that didn’t have it.

    LDAPAdmin – My favorite LDAP browser/administrator.  I’ve used this a LOT, and it has been a real life saver!

    Angry IP Scanner– I use this regularly to scan subnets for active hosts.  It also has port scanning capabilities, but I seldom use these.

    IPerf – Bandwidth client/server testing tool.  You can test from one laptop to another across a link to see what kind of BW you get.  Be sure to test straight from laptop to laptop with a crossover cable first.  Windows machines can be a little strange at times.

  • Cacti Tutorial – Add Syslog and SNMP to your Cisco Devices

    Here we go. This adds syslog and SNMP to your Cisco switches and routers. This also includes steps on adding an access list to only allow the cacti server to poll via SNMP. Click the link below to see the video!
    (more…)

  • What is Autoit?

    Here’s another product I couldn’t live without as an engineer.  I am a network engineer, but I’ve been doing server admin since the beginning of my career.  I also have my degree in computer science, so…I still like to program occasionally.  I am an efficient programmer, or lazy, however you want to look at it.  I want to be able to go start to finish on a script or program as quickly as possible.  This is why I latched onto VB6 back in the day.  I could start a new project, click save, and I had a working program.  Autoit is much the same, only better in some ways…did I mention it is completely free!

    Autoit began life as a way to automate tasks in windows.  Say if you wanted to have it auto install a program and click a few buttons for you.  It has gone WAY beyond those humble beginnings.  It has com support, can use tcp sockets, has decent gui capabilities, can pack in files and has basic like syntax.  If you know and love the VB6 command structure, you will be right at home.  The help file is your first stop for anything, second are the forums.  The example code in both is phenomenal.

    So, what have I used Autoit for:

    • Backup folder retention – keeps one week’s worth of files in it.
    • Serial LCD control
    • Parsing through a few hundred bind9 configs and updating them
    • SNMP polling of various kinds of devices
    • Stick adding for fantasticcontraption…I like to make catapults
    • FTPing files on a schedule
    • Checking IIS SMTP relay – send test email, check queue folder
    • Parse an LDIF from an LDAP server
    • Make a soundboard
    • Connect to all our L2 devices and pull configs, then parse and arrange all vlans on all devices
    • Parse the admin script from a WoW Mangos server and email all admins specific actions…Keeps admins from using .die all the time.

    You will see me post my scripts from time to time.

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