Ondrej Žilinec – IT Blog

Today I was needed to make batch script to ping some IP addresses for problem described in this article. My first script was as following:

@Echo Off

:Loop1

ping 1.1.1.1 -n 1 -w 30000 >NUL

ping 8.8.8.8 -n 1 | find /i “bytes=” || goto FailedPing

goto Loop1

:FailedPing

echo FAILED PRIMARY NET TO VIA 10.0.0.1 %time% >>ping_test.log

route delete 0.0.0.0 mask 0.0.0.0 10.0.0.1

route add 0.0.0.0 mask 0.0.0.0 10.0.0.2

goto Loop1

When I ran this script in cmd.exe or I scheduled it, it ate one CPU core. I didn’t know why it’s happening, because when I ran this commands in cmd.exe separatelly it workied fine. After couple minutes of debugging I found out that script is not waiting for “ping” commands to finish. It was weird. My colleague told me to use “sleep.exe” to make it wait for a little bit. But that was not a solution. I wanted to force it to wait for ping commands. I tried weird thing. Instead of “ping” I used whole path for ping.exe “%SystemRoot%\\System32\\ping.exe” and for command “route” I used “%SystemRoot%\\System32\\route.exe”. Now everything looks and works perfect.

I have no idea why this is happening, but it works and I need to remember it 🙂

When I upgraded from ISA 2006 to TMG 2010 I found some special problem. There was HQ with TMG 2010 and one branch with ASA 5505. Between those two location there was Site to Site VPN tunnel created. Everything worked fine, beside one problem. Users in branch couldn’t access anything on TMG server. They couldn’t ping it or do anything with it. They couldn’t browse Internet, because TMG was also web proxy server for them.

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Customer wanted to upgrade his ISA 2006 server to “new” TMG 2010. I thought it would be nice and easy process. It could be if there were no problems which I didn’t expect to be a problem in “new” software. Old server was still functional and I wanted to prepare new server and migrate all settings and certificates.

Requirements

To install all requirements you can install required packages by yourself or you can use Run Preparation Tool from installation screen of TMG. Why didn’t they include it into installation package it self?

Messed up console

When I was done with installation I ran TMG console and I received following error:

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We had project replacing SAN switches. Customer has one old HP-UX (HP Unix) system. This system is very sensible about SAN changes.

Normal situation

You can see all hardware using command (http://www.bga.org/~lessem/psyc5112/usail/man/hpux/ioscan.1.html):

ioscan -fnC

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Most of you probably already updated Active Directory infrastructure from Windows 2003 to Windows 2008 R2. What I see most is that administrators do not upgrade DFS replication subsystem for SYSVOL shares. Before Windows Server 2008 (also R2) was released FRS (File Replication System) is used. In Windows 2008 R2 there is new version released and it’s called DFSR (Distributed File System Replication).

FSR

FSR uses NTFS volumes’ USN journal to determine when a change has occured to a file and triggers replication. When FSR detects file close it gathers information about file and it’s attributes. It also checks file’s MD5 hash. If MD5 hash changes it will trigger replication. If file has changed whole file is send to FSR replication partners.

DFSR

First benefit of DFSR is that it doesn’t replicate whole file, but just a changed data in the file. To be able to check only changes in files it uses RDC (Remote Differential Compression) compression algorithm.

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I was wondering what would Windows XP payload to be. I always thought that there will be random characters or something like that, but I was wrong.

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Hello all

Today I earned another Cisco certificate.

I played with HP Procurve switches and I found one weird default setting. Spanning Tree Protocol is disabled by default. It was weird finding because I tried to interconnect two switches with pair of cables whole my network went down 🙂 It was overloaded with b-cast storm.

Today I was facing weird problem at our customer. They have IBM HS21 blade server with build-in dual-port Broadcom network card. There was only Windows 2008 installed with all up2date drivers. Everything worked fine besides network performance. Upload from server to other servers was around 20MBps, which is fine. Problem was download to server, because it was 1-2MBps.

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Veľa krát sa stretávam u zákazníkov s tým, že ľudia sa sťažujú na rôzne posuny časov tak na ich klientských počítačoch ako aj na serveroch. Read more…