Port 80 not able to be seen remotely

Hi All,

We are experiencing a rather strange issue here.

We run an internal web site for internal clients to
access on one subnet. Users of that subnet are able to
access the web server fine. However, users from other
remote subnets are not able to connect to the web server.
They get a message saying page cannot be displayed.

There doesn't seem to be any issues with permissions or
DNS resolution as they are able to ping via IP and host
name without issues. However, doing a port scan from a
remote subnet, port 80 cannot be seen. But doing a scan
for port 80 on the local subnet, it is visible. I've
checked with our router and firewall consultants, and
they have advised that port 80 is not blocked or on any
ACLs.

Is there a possiblility that Windows 2003 IIS is blocking
port 80 for remote subnets somehow? I don't think this
could the problem though, as in IIS, all domains are
allowed access to the web site.

Can anyone suggest which other potential issues could be
blocking http traffic remotely?

The setup here is quite simple. The local subnet is based
at HQ in one city. The remote subnets is connected via
private DSL WAN link through Cisco 1700 series router in
other cities.

As a test, i enabled telnet on its default port, and the
same results. I was able to telnet to the web server on
the local subnet, but not from remote subnets.

Could this mean, some sort of rule on the router and
firewall are blocking the telnet ports as well?

Thanks,
Sung

Hi All,

Ignore this request. I ended up changing the IP address
of the web server and everything seems to be working okay.

Still a little unclear as to why port 80 was being
blocked, as the address is still in the same subnet as
the previos one.

Regards,
Sung
>-----Original Message-----
>Hi All,
>
>We are experiencing a rather strange issue here.
>
>We run an internal web site for internal clients to
>access on one subnet. Users of that subnet are able to
>access the web server fine. However, users from other
>remote subnets are not able to connect to the web
server.
>They get a message saying page cannot be displayed.
>
>There doesn't seem to be any issues with permissions or
>DNS resolution as they are able to ping via IP and host
>name without issues. However, doing a port scan from a
>remote subnet, port 80 cannot be seen. But doing a scan
>for port 80 on the local subnet, it is visible. I've
>checked with our router and firewall consultants, and
>they have advised that port 80 is not blocked or on any
>ACLs.
>
>Is there a possiblility that Windows 2003 IIS is
blocking
>port 80 for remote subnets somehow? I don't think this
>could the problem though, as in IIS, all domains are
>allowed access to the web site.
>
>Can anyone suggest which other potential issues could be
>blocking http traffic remotely?
>
>The setup here is quite simple. The local subnet is
based
>at HQ in one city. The remote subnets is connected via
>private DSL WAN link through Cisco 1700 series router in
>other cities.
>
>As a test, i enabled telnet on its default port, and the
>same results. I was able to telnet to the web server on
>the local subnet, but not from remote subnets.
>
>Could this mean, some sort of rule on the router and
>firewall are blocking the telnet ports as well?
>
>Thanks,
>Sung
>.
>