nettracer
Windows 2012 R2 server fails to establish outbound connections
Hi there, It's been a very long while since I have blogged something here and it's time to come back...
Date: 01/11/2018
Testing Lync server 2013 external URLs from Lync clients (external web service, meet, office webapps, lyncdiscover and dialin)
Hi there, In this blog post, I’ll be talking about another powershell based tool which could...
Date: 05/21/2014
Testing Exchange EWS service accessibility from internal/external Lync clients
Hi there, In this blog post, I’ll be talking about a powershell based tool which could be used...
Date: 05/21/2014
How it works on the wire: IIS HTTP Client certificate authentication
I collaborated with a colleague recently where the IE client was failing to authenticate to IIS and...
Date: 12/30/2013
DNS SRV lookup from Powershell
[After posting this blog, I have realized that Powershell 3.0 already provides a built-in cmdlet...
Date: 10/13/2013
Testing STUN/TURN server connectivity from external networks through UDP 3478 by using Powershell
Hi there, While working on a Lync connectivity test tool, I developed a STUN/TURN server...
Date: 10/13/2013
External Lync 2013 clients cannot upload ppt or other files and whiteboard, poll, Q&A are greyed out on Lync client
Hi again, In this blog post, I want to talk about a Lync 2013 problem where external users fail to...
Date: 10/12/2013
Decrypting SSL/TLS sessions with Wireshark - Reloaded
Hi there, In a previous blog post of mine, I went through the steps of decrypting SSL/TLS traffic by...
Date: 10/12/2013
Running Lync 2013 WebApp plugin in locked down Terminal server environments
Hi there, In this blog post, I would like to talk about running Lync 2013 Webapp in Windows Terminal...
Date: 08/04/2013
Event ID 56417 may be logged on Lync server 2013 intermittently
Hi again, I dealt with a Lync server 2013 problem recently where the server was intermittently...
Date: 07/08/2013
Lync 2013 client may crash when Organization tab is clicked
Hi there, I was dealing with a Lync 2013 client crash problem a few months ago and I wanted to...
Date: 07/08/2013
Cumulative update version information for Lync client and Lync server
[Last updated on 27th February, 2014] Hi there, You can find a list of CU versions compiled from KB...
Date: 07/05/2013
Exchange integration error on HP4120 desktop phones - A CA trust issue
I would like to go through an integration problem between Lync phone edition devices and Exchange...
Date: 01/18/2013
Lync 2010 response group members phones keep ringing even if the remote party hangs up the phone
In this blog post, I’ll be talking about a response group problem where the response group...
Date: 01/18/2013
RDP connections might fail due to a problem with KB2621440 - MS12-020
I was helping a colleague who was dealing with a Remote desktop connection problem where Windows 8...
Date: 01/18/2013
Desktop sharing fails between federated contacts running Lync 2010 clients
I would like to talk about another Lync 2010 problem where desktop sharing was failing between two...
Date: 01/18/2013
External users cannot sign in to Lync 2010
Today I’ll be talking about a problem where the external Lync 2010 clients fail to sign in...
Date: 01/18/2013
SCCM client push installation may fail due to firewall problems
I was collaborating with a colleague of mine on a problem where SCCM client push installation was...
Date: 01/06/2013
TMG Safe search feature may not work as expected sometimes
In this post, I would like to talk about a TMG safe search problem which I dealt with recently. The...
Date: 01/06/2013
Slow performance when accessing a Sharepoint 2010 portal through an ISA 2006 array
I was involved in a slow Sharepoint portal access through an ISA 2006 array problem and I wanted to...
Date: 01/06/2013
Direct access client fails to connect to UAG DA server through IPHTTPS with various errors (0x800b0109 and 0x274c)
In this post, I want to talk about how I troubleshooted a direct access connectivity problem hoping...
Date: 01/06/2013
TCP delayed ACK combined with Nagle algorithm can badly impact communication performance
Recently I was involved in a network connectivity performance issue and wanted to share the root...
Date: 01/05/2013
Network trace analysis tricks III - How can I comment on packets in a network trace
After you get familiar with using protocol analysis tools like Network Monitor or Wireshark,...
Date: 07/11/2012
Network trace analysis tricks II - How can I focus on a certain packet range in a network trace?
In the second post of “network analysis tricks” series, I’ll explain how to focus...
Date: 06/27/2012
Network trace analysis tricks I - How can I see all TCP connection attempts in a network trace?
In the “network analysis tricks” series of posts, I’ll try to explain some...
Date: 06/22/2012
Network traffic capturing hints
In this post, I would like to talk about some important points about network capturing. If a network...
Date: 06/22/2012
When do we need to collect network traces?
Many Microsoft support engineers dealing with customer technical issues ask for network traces to...
Date: 06/22/2012
HTTPS access through TMG fails from a certain VLAN with a very unusual error: FWX_E_SEQ_ACK_MISMATCH
In this blog post, I’ll be talking about an interesting problem that I dealt with recently....
Date: 06/15/2012
Outlook anywhere (RPC over HTTPS) access to Exchange 2010 server via TMG 2010 fails after some time
In this blog post, I’ll be discussing an Exchange 2010 publishing on TMG 2010 issue. The...
Date: 06/12/2012
Getting HTTP 500 Internal server error when accessing a published web site through ISA 2004
In this post, I’ll be talking about a web publishing problem and how I dealt with it. The...
Date: 05/23/2012
Outlook MAPI connection to Exchange 2010 CAS fails through UAG 2010 direct access tunnel
In a recent case, I dealt with an Outlook MAPI connection failure problem through direct access...
Date: 05/22/2012
PDF file corrupted when downloaded through TMG server
Recently I dealt with a problem where PDF file downloaded from a certain external web site was...
Date: 05/21/2012
Internet Explorer doesn't display ISA or TMG error message 502 when connecting to HTTPS servers
Hi there, I would like to talk about an issue that I have dealt with recently regarding Internet...
Date: 09/22/2011
TMG initiates active FTP connections to external servers even though it's configured for passive FTP - a problem with FTP over HTTP
Hi there, In this blog post, I’ll be talking about another TMG problem where FTP over HTTP was...
Date: 09/21/2011
Java applications and TMG access rules that require authentication
Hi there, In this blog post, I’ll be talking about a TMG related issue. Actually it’s...
Date: 09/21/2011
Anatomy of a DoS attack that exploits WebDAV vulnerability in Apache Web server
Hi there, It has been sometime since I haven’t posted anything at the blog and finally got a...
Date: 09/08/2011
How it works under the hood: A closer look at TCPIP and Winsock ETL tracing on Windows 7 and Windows 2008 R2 with an example
Hi there, In this blog post, I would like to talk about TCPIP, Winsock ETL tracing a bit with an...
Date: 10/06/2010
SCCM packages may be distributed slower than standard file copy (xcopy/Windows Explorer)
Hi there, In this post, I’m going to mention about another issue where I helped a colleague of...
Date: 10/05/2010
SQL Browser may not be reachable through firewalls when it runs on a cluster
Hi there, In this blog post, I would like to talk about a problem in which I was involved as a...
Date: 10/05/2010
Bogus IP packets and Wireshark
Hi there, In today’s blog post, I’m going to talk about an issue that I have come across...
Date: 10/05/2010
How to decrypt an SSL or TLS session by using Wireshark
[Updated on 26th October 2013] The following blog post is the newer version of this blog post:...
Date: 10/01/2010
Why are local resources accessed slowly when loopback or local IP address is used whereas accessing the same resources over the network works fine?
Hi there, In today’s blog post, I’m going to talk about a local resource access...
Date: 08/16/2010
Effects of incorrect QoS policies: A story behind a slow file copy...
Hi there, In this blog post, I’ll talk about another network trace analysis scenario. The...
Date: 08/11/2010
Where have those AFD driver related registry (DynamicBacklogGrowthDelta / EnableDynamicBacklog ...) keys gone?
Hi there, In today’s blog post, I’m going to talk about some registry keys that were...
Date: 08/11/2010
Does sqllogship.exe have anything to do with web servers in the internet? Story behind CRL check for certificates ...
Hi there, In today’s blog post I’m going to talk about a network trace analysis scenario...
Date: 08/09/2010
Where are my packets? Analyzing a packet drop issue...
One of the most common reasons for network connectivity or performance problems is packet drop. In...
Date: 08/06/2010
Is it real or Matrix? Some facts about network traces...
Hi there, In this blog post, I would like to talk about some facts about network traces. A while ago...
Date: 08/05/2010
Excessive ARP requests, is it malware or legitimate activity?
Hi there, In this blog post, I would like to talk about a network trace analysis scenario where we...
Date: 08/05/2010
Why does it take too long to retrieve data from SQL server over a WAN connection?
Hi there, In today’s blog post, I’m going to talk about how to troubleshoot a WAN...
Date: 08/05/2010
Exchange servers send ICMP and UDP packets to clients or Domain Controllers, why?
Hi, I would like to talk about a few network trace analysis cases where we were requested to find...
Date: 08/04/2010