Tag Archives: TCP

Rpcrt4.dll – Revision History for Windows Vista SP2, Windows Server 2008 SP2 and Windows Small Business Server 2008 (SBS 2008)

Rpcrt4.dll – Revision History for Windows Vista SP2, Windows Server 2008 SP2 and Windows Small Business Server 2008 (SBS 2008)

10-Jul-2013 – 6.0.6002.23155 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/2849470 – MS13-062: Vulnerability in remote procedure call could allow elevation of privilege: August 13, 2013

10-Jul-2013 – 6.0.6002.18882 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/2849470 – MS13-062: Vulnerability in remote procedure call could allow elevation of privilege: August 13, 2013

13-Mar-2011 – 6.0.6002.22611 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/2521448 – RPC returns an out-of-memory error incorrectly when you use an RPC over HTTP client to connect to an RPC over HTTP server in Windows Server 2008 or in Windows Vista

04-May-2010 – 6.0.6002.22398 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/2023170 – An access violation exception occurs in the “NdrClientCall2” function in Windows Vista or in Windows Server 2008

18-Jul-2009 – 6.0.6002.22180 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/973780 – Some TCP connections between an NLB server that is running Windows Server 2008 and its clients are broken after the Port Scalability feature is enabled on the NLB server

23-Apr-2009 – 6.0.6002.22120 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/970238 – MS09-026: Vulnerability in RPC could allow elevation of privilege

23-Apr-2009 – 6.0.6002.18024 – Rpcrt4.dll – x86/x64 – http://support.microsoft.com/kb/970238 – MS09-026: Vulnerability in RPC could allow elevation of privilege

Microsoft Windows 7 or Windows Server 2008 R2 – BITS client will reset the TCP connection each time is downloads a range of the file and increases overall network traffic

Microsoft Windows 7 or Windows Server 2008 R2 – BITS client will reset the TCP connection each time is downloads a range of the file and increases overall network traffic.

You can find more information and the download link for a hotfix that addresses the issue in Microsoft KB 2654875 http://support.microsoft.com/kb/2654875

Microsoft Windows Vista and Windows Server 2008 – TCP/IP Registry Values

This Microsoft White Paper discusses how you can modify TCP/IP behavior with registry values.  This guide applies to Windows Vista and Windows Server 2008

Microsoft guide can be found here:

http://www.microsoft.com/download/en/details.aspx?id=9152&WT.mc_id=rss_windows_vista

Watchguard – SSL VPN clients cannot resolve internal host names despite DNS servers being configured for the connection

You may find that when you configure your Watchguard XTM Firewall to accept SSL VPN connections that clients can connect to

the VPN and ping IP addresses of internal resources, however you cannot resolve internal hosts even via FQDN using DNS.  You

may also find that when you run NSLOOKUP on the SSL VPN connected client that the  result is your Internet Service Providers

DNS servers rather than the DNS servers assigned via the VPN connection.

 

To resolve the issue you can change your SSL VPN configuration from a “Routed VPN” to a “Bridge VPN”, the routed VPN uses a

virtual IP address pool (192.168.113.0/24) which does not match your internal IP range or the address range of the internal

DNS Servers.  When a Windows client connects to the “Routed VPN” it appears that due to the DNS server mismatch they are not

utilised by the client.

 

When you configure the VPN in “Bridge VPN” mode you can work around this issue, the Bridge VPN configuration allows you to

exclude some addresses from your Windows DHCP Server Pool and add the into them “Start” and “End” IP addresses on your

Watchguard SSL VPN Configuration Page. The Watchguard will now become responsible for assigning these internal IPs to VPN

clients as they connect rather than the Windows DHCP Server.

 

You should now find that when your SSL VPN clients connect that they are assigned an IP address and DNS server that are all

within the existing internal IP range of your network.  An NSLOOKUP should now return your internal DNS server address and

you should be able to ping hostnames and FQDNs that reside within your internal network.

 

Examples:

ping windowsserver

ping windowsserver.exampledomain.local

 

Please remember that the only down side with this configuration is that a “Bridge VPN” bridges to the “Trusted” interface,

this means that the client computer can access any internal resources that they have permissions for by default. A “Routed

VPN” allows you to offer traffic to Optional/secondary networks and gives you more control by letting you lock down access

using “Specify allowed resources”.