Router dropping packets and blocking Remote Desktop connection

22 Aug 2006 10:27 PM

go_to_bed_late

I have an odd problem and I am hoping for some guidance or input.

I have an application which runs using Remote Desktop. This is on a
remote network. Until very recently the connection to the remote server
could be made and the application worked fine.

I have done the following

1. Connected direcctly to the modem - Remote Connection success

2. Connected to the server from a different network - Remote Connection
success

3. Tested Remoet Desktop on the remote server - Remote Connection
success

When I attempt to connect I get the usual message "Cannot
connect........"

It appears from the router firewall log that it is blocking connections

The router is a Linksys BEFSX41

Basically I am wondering if anyone has come across this problem? It is
clear to me that the router is the issue but I can't see why port 3389
is the only one that is all of a sudden being blocked. All other
services work fine and from what I can see no changes have been made to
the router. Any thoughts appreciated.

Thanks

23 Aug 2006 1:48 AM

Robert L [MS-MVP]

It could be the MTU issue. these search results may help,

Black screen when rdp over vpn Troubleshooting: Since this is DSL line, we suspect this is MTU issue. ... Resolution: Use the ping to test and lower MTU. Finally, We reduce MTU from 1500 ...
      www.howtonetworking.com/casestudy/mtu1.htm

      connection to remote computer was broken caused by network error To change the MTU Settings, select the the following ... How to modify the MTU ... I would check the MTU first. Or check this link: vpn drop connection . ...
            www.chicagotech.net/Q&A/vpn54.htm

      Can't access RDC over VPN I would check the MTU first. Or check this link: vpn drop connection ... This step-by-step article describes how to modify the default MTU size settings ...
            www.chicagotech.net/Q&A/vpn47.htm

Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com

"go_to_bed_late" <x2404***@hotmail.com> wrote in message news:1156285654.744995.57020@h48g2000cwc.googlegroups.com...

I have an odd problem and I am hoping for some guidance or input.

I have an application which runs using Remote Desktop. This is on a
remote network. Until very recently the connection to the remote server
could be made and the application worked fine.

I have done the following

1. Connected direcctly to the modem - Remote Connection success

2. Connected to the server from a different network - Remote Connection
success

3. Tested Remoet Desktop on the remote server - Remote Connection
success

When I attempt to connect I get the usual message "Cannot
connect........"

It appears from the router firewall log that it is blocking connections

The router is a Linksys BEFSX41

Basically I am wondering if anyone has come across this problem? It is
clear to me that the router is the issue but I can't see why port 3389
is the only one that is all of a sudden being blocked. All other
services work fine and from what I can see no changes have been made to
the router. Any thoughts appreciated.

Thanks

2 Sep 2006 12:53 PM

go_to_bed_late

Yes MTU was the problem.

Thanks for your help.

Robert L [MS-MVP] wrote:

Show quoteHide quote

> It could be the MTU issue. these search results may help,
>
> Black screen when rdp over vpn Troubleshooting: Since this is DSL line, we suspect this is MTU issue. ... Resolution: Use the ping to test and lower MTU. Finally, We reduce MTU from 1500 ...
>       www.howtonetworking.com/casestudy/mtu1.htm
>
>       connection to remote computer was broken caused by network error To change the MTU Settings, select the the following ... How to modify the MTU ... I would check the MTU first. Or check this link: vpn drop connection . ...
>             www.chicagotech.net/Q&A/vpn54.htm
>
>
>       Can't access RDC over VPN I would check the MTU first. Or check this link: vpn drop connection ... This step-by-step article describes how to modify the default MTU size settings ...
>             www.chicagotech.net/Q&A/vpn47.htm
>
>
>
>
> Bob Lin, MS-MVP, MCSE & CNE
> Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
> How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
>   "go_to_bed_late" <x2404***@hotmail.com> wrote in message news:1156285654.744995.57020@h48g2000cwc.googlegroups.com...
>   I have an odd problem and I am hoping for some guidance or input.
>
>   I have an application which runs using Remote Desktop. This is on a
>   remote network. Until very recently the connection to the remote server
>   could be made and the application worked fine.
>
>   I have done the following
>
>   1. Connected direcctly to the modem - Remote Connection success
>
>   2. Connected to the server from a different network - Remote Connection
>   success
>
>   3. Tested Remoet Desktop on the remote server - Remote Connection
>   success
>
>   When I attempt to connect I get the usual message "Cannot
>   connect........"
>
>   It appears from the router firewall log that it is blocking connections
>
>   The router is a Linksys BEFSX41
>
>   Basically I am wondering if anyone has come across this problem? It is
>   clear to me that the router is the issue but I can't see why port 3389
>   is the only one that is all of a sudden being blocked. All other
>   services work fine and from what I can see no changes have been made to
>   the router. Any thoughts appreciated.
>
>   Thanks
>
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> <DIV>It could be the MTU issue. these search results may help,</DIV>
> <DIV> </DIV>
> <DIV><A class=l href="http://www.howtonetworking.com/casestudy/mtu1.htm"><FONT
> color=#663399>Black screen when rdp over vpn</FONT></A>
> <TABLE cellSpacing=0 cellPadding=0 border=0>
>   <TBODY>
>   <TR>
>     <TD class=j>
>       <DIV><FONT size=-1>Troubleshooting: Since this is DSL line, we suspect
>       this is <B>MTU</B> issue. <B>...</B> Resolution: Use the ping to test and
>       lower <B>MTU</B>. Finally, We reduce <B>MTU</B> from 1500
>       <B>...</B><BR><FONT color=#008000><A
>       href="http://www.howtonetworking.com/casestudy/mtu1.htm">www.howtonetworking.com/casestudy/<B>mtu</B>1.htm</A></FONT></FONT></DIV>
>       <DIV><FONT color=#008000 size=2></FONT> </DIV>
>       <DIV>
>       <P class=g><A class=l
>       href="http://www.chicagotech.net/Q&A/vpn54.htm"><FONT
>       color=#663399>connection to remote computer was broken caused by network
>       error</FONT></A>
>       <TABLE cellSpacing=0 cellPadding=0 border=0>
>         <TBODY>
>         <TR>
>           <TD class=j><FONT size=-1>To change the <B>MTU</B> Settings, select
>             the the following ... How to modify the <B>MTU</B> <B>...</B> I
>             would check the <B>MTU</B> first. Or check this link: vpn drop
>             connection . <B>...</B><BR><FONT color=#008000><A
>             href="http://www.chicagotech.net/Q&A/vpn54.htm">www.chicagotech.net/Q&A/vpn54.htm</A>
>             </FONT></FONT></TD></TR></TBODY></TABLE>
>       <P class=g><A class=l
>       href="http://www.chicagotech.net/Q&A/vpn47.htm"><FONT
>       color=#663399>Can't access RDC over VPN</FONT></A>
>       <TABLE cellSpacing=0 cellPadding=0 border=0>
>         <TBODY>
>         <TR>
>           <TD class=j><FONT size=-1>I would check the <B>MTU</B> first. Or
>             check this link: vpn drop connection <B>...</B> This step-by-step
>             article describes how to modify the default <B>MTU</B> size settings
>             <B>...</B><BR><FONT color=#008000><A
>             href="http://www.chicagotech.net/Q&A/vpn47.htm">www.chicagotech.net/Q&A/vpn47.htm</A>
>              
> </FONT></FONT></TD></TR></TBODY></TABLE></P></DIV></TD></TR></TBODY></TABLE></DIV>
> <DIV><BR>Bob Lin, MS-MVP, MCSE & CNE<BR>Networking, Internet, Routing, VPN
> Troubleshooting on <A
> href="http://www.ChicagoTech.net">http://www.ChicagoTech.net</A> <BR>How to
> Setup Windows, Network, VPN & Remote Access on <A
> href="http://www.HowToNetworking.com">http://www.HowToNetworking.com</A> </DIV>
> <BLOCKQUOTE
> style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
>   <DIV>"go_to_bed_late" <<A
>   href="mailto:x2404***@hotmail.com">x2404***@hotmail.com</A>> wrote in
>   message <A
>   href="news:1156285654.744995.57***@h48g2000cwc.googlegroups.com">news:1156285654.744995.57020@h48g2000cwc.googlegroups.com</A>...</DIV>I
>   have an odd problem and I am hoping for some guidance or input.<BR><BR>I have
>   an application which runs using Remote Desktop. This is on a<BR>remote
>   network. Until very recently the connection to the remote server<BR>could be
>   made and the application worked fine.<BR><BR>I have done the
>   following<BR><BR>1. Connected direcctly to the modem - Remote Connection
>   success<BR><BR>2. Connected to the server from a different network - Remote
>   Connection<BR>success<BR><BR>3. Tested Remoet Desktop on the remote server -
>   Remote Connection<BR>success<BR><BR>When I attempt to connect I get the usual
>   message "Cannot<BR>connect........"<BR><BR>It appears from the router firewall
>   log that it is blocking connections<BR><BR>The router is a Linksys
>   BEFSX41<BR><BR>Basically I am wondering if anyone has come across this
>   problem? It is<BR>clear to me that the router is the issue but I can't see why
>   port 3389<BR>is the only one that is all of a sudden being blocked. All
>   other<BR>services work fine and from what I can see no changes have been made
>   to<BR>the router. Any thoughts
> appreciated.<BR><BR>Thanks<BR></BLOCKQUOTE></BODY></HTML>
>
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