Article ID: 169268
Article Last Modified on 6/23/2005
APPLIES TO
- Microsoft Internet Information Server 3.0
This article was previously published under Q169268
We strongly recommend that all users upgrade to Microsoft Internet Information Services (IIS) version 6.0 running on Microsoft Windows Server 2003. IIS 6.0 significantly increases Web infrastructure security. For more information about IIS security-related topics, visit the following Microsoft Web site:
SYMPTOMS
When you try to connect to a site via FTP, you may get the following
error message after a few minutes if the Internet Information Server (IIS)
is configured with more than one default gateway:
Error: Connection timed out
This may also happen only when you try to connect via FTP using a slow
link (for example, a 28.8k modem connection) to a server that has more
than one default gateway.
CAUSE
The IIS computer should have only one IP default gateway. The IP address
of the default gateway should be configured on the external network
adapter card only.
This requirement is a result of the basic architecture of TCP/IP. Only
one default gateway must be defined on a host that resides on two or
more non-connected networks.
If IIS server is configured with more than one network interface, it is
connected to two networks that are by design non-connected.
A default gateway is a router that is supposed to be used for all traffic
that has no specific route. If you have two default-gateways, the IIS
server TCP/IP stack will assume that they lead to the same set of
networks. This will cause the IIS server to send Internet traffic to
the internal network, or internal traffic to the Internet.
WORKAROUND
Remove the default gateway from the advanced TCP/IP settings of the
internal network interface on the IIS server and define static routes to
the internal network segments.
For additional information, please see the following Microsoft Knowledge
Base article:
161380
: Only One Default Gateway Allowed On Proxy Server
Because no default gateway will be defined for the internal network, you
must add static routes using the Route Add command. These routes can be
made persistent by using the -p command switch.
Additional query words: proxy internet server timeout connect fail winsock ftp iis
Keywords: kbprb kbusage KB169268