Re: Cannot open link on college web course page...

"-Kel" wrote ...

I pinged Yahoo and that did work. WebCT is a web based program that teachers
can use to set up homework assignments and tests for the students to take
online which is offered through the college or university. I would log on to
the school's site and they would have a link set up that should take you
directly to the site the teacher set up.

I did the nslookup and have retrieved their IP address, I tried that to no
avail either.

the tracert came back with 30 'hops' and on #11 the request timed out all
the way to #30.


Then the route from you to their host is broken. Routes are not dynamic; that is, they do not instantaneously try alternate routes when the recorded one fails. Each routing table gets updated with a path through the next host to get to the target but it is not dynamically updated, like when there is a host down in the path. You can call your ISP to tell them to update their routing table to make sure they have a correct path between your host and the target. However, they may end up getting the same route. You could complain to the target host's provider but that won't do any good because you are not their customer (and they likely only handle requests from their own customers), so sent the complaint to the target web site to have their provider update their routing table. If it is somewhere between the endpoints then you have to wait it out until the route starts working, or you could give the unresponsive host to your own ISP and ask them to use a route that doesn't use that host.

The route that you current get is dead. It dies at the host listed last in your traceroute. Since you didn't provide an IP address for the target, I cannot perform a traceroute to see if it works from here. Often a route from one endpoint works okay from an endpoint in a different area. That's why sometimes you can get to the target by using a public proxy that ends up using a different route. One time, I couldn't get to a Creative Labs network somewhere down southeast USA because one of their boundary hosts was unresponsive, so I tried a slew of proxies trying to get a different route to their network that would hit a different boundary host and get me in. Once I figured out which of their boundary hosts was defective, I reported it to them and they fixed it in a day (they took it out in the meantime so no one else would hit it).

http://en.wikipedia.org/wiki/Routing_tables

Someone else more intimate with routing tables and RIP or other routing algorithms can explain just when they do get updated. It certainly doesn't seem like they are instantaneous or immediately updated to go searching for alternate routes. If the route is dead, it remains dead to the user until the defective host becomes responsive or the routing table gets changed (and I'm not sure of when or how it gets changed). I just know that if the route is dead that I report it to my ISP and report it to the target site (using alternate routes through proxies or e-mailing them) and hope the host or route gets eventually fixed or changed.

.

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