inaccessible web site

[familyman]

I have a Cisco 2621 router connected to my ISP via a T1 line and connected to my network via 100BaseT and a 3com switch. On my network, I have configured an IIS web server and have a DNS entry that points to the machine on which IIS is running. I am able to access my web site from most remote locations, but I am unable to access it from some.<br>
<br>
When I log on to an ISP from which I am unable to access my site and ping the machine (or any machine on my network) via IP Address or by name, I get a request timed out message. <br>
<br>
The strange thing is that while I am able to ping the serial port of the router that feeds the switch (where the T1 enters the router) - I am unable to ping the ethernet port that goes out from the router to the switch that feeds my network.<br>
<br>
Do I have something configured incorrectly on my Cisco router? Or could this be a DNS issue? As I mentioned - it works fine from some remote locations, but not from others.<br>
<br>
Thanks in advance for your help.<br>

 

[jfk]

familyman:<br>
<br>
Is this a recent DNS addition? It can take up to a week or more for new DNS entries to propagate. From where are there difficulties? Do you have any ACLs configured on the router?<br>
<br>
jfk

 

[familyman]

jfk -<br>
<br>
The internic registration was sent in about 4 weeks ago.<br>
<br>
We are running primary DNS ourselves with our ISP providing secondary DNS.<br>
<br>
An instance of not being able to access my web site would be when I dial in to my ISP (surfree.com) using a Denver, CO. number. However using the same connection, I telnet out to a site I have access to in Sioux Falls then ping my web site from there - it works.<br>
<br>
I am new to networking and not familiar with router configuration. The router was configured prior to my coming on board, and I was hoping I wouldn't have to get into it at that level, but it looks like I might.

 

[jfk]

familyman:<br>
<br>
Hmmm, can you ping your web server from your ISP account? Or is it just web access that you don't have? To check for a DNS issue, try using the IP address to open the web page. If it doesn't work, also run a traceroute to see where you're getting to (and not).<br>
<br>
jfk

 

[familyman]

jfk:<br>
<br>
I am unable to ping my web server via name or ip address.<br>
<br>
when I try a traceroute I get this:<br>
<br>
C:&gt;tracert 209.174.109.130<br>
<br>
Tracing route to 209.174.109.130 over a maximum of 30 hops<br>
<br>
1 * * * request timed out<br>
2 * * * request timed out<br>
etc, etc to 30 hops<br>
<br>
however I can ping the serial port (T1 line on my local router)<br>
<br>
what's strange is that you would think the above trace route would be good up until the point it hits my router at least, since I can ping my router.

 

[jfk]

familyman:<br>
<br>
Your ISP could be filtering ICMP from the filter. Did you try to open the web page with just the IP address?<br>
<br>
jfk

 

[ITAddiction]

Hello,
Has this ever worked since the Dns change ?

If you are pinging from the ISP side then i wouldnt expect you be able to ping anymore than the wanside serial interface.

Another thing you could do is run debug on the router and see what requests are coming in on that interface.

Steve IT Addiction