On Fri, 2004-01-02 at 00:14, Vidiot wrote: > I'm curious, how does the ISP using a cache server save bandwidt? I can see it > if the requests are coming from their clients to web pages outside, but how > does it help when web page requests come from outside users to web pages that > are inside? The outside bandwidth is still used. Bandwidth inside their controlled network is used, but no additional traffic from the ISP through their core network to others' networks are used. Example: 20 customers in the same network request a page in *.yahoo.com. The ISP caches it after collecting it the first time. The next 19 customers receive a cached copy. Yes, bandwidth inside the network was used, but it was THEIR OWN network (read: cheap[er]). Those other 19 object requests did not have to cross transit networks. > I'm still confused as to how any kind of DNS lookup is going to make a > difference in the routing of the HTTP packets. All DNS is for is to convert > the "www.simpaticus.com" into an actual IP address. At that point the box > then sends an HTTP request to that IP address. In my case, the IP addess > is the SAME box that the HTTP request from the browser is coming fro and > going to. Are you telling me that the Linux routing software will take that > IP request and send it to my ISP's router/gateway, only to have it returned > to me? Doesn't it make more sense that Linux routing would internally route > that request witin itself, never even placing the packets on my DSL circuit? > I would expect it to work the same way as it does when I use localhost in the > URL address (which is what I normally do anyway). This is really getting off-topic and beyond scope. Please refer to those books I mentioned. You need a better understand of how the Internet "works" with respect to routing, and preferably, DNS. Google for split-horizon DNS, rather than wasting your time in this thread. > I do not disagree with ISPs trying to save money, but when a cahe proxy > works as badly as the one they are using, it has to hurt their customers. > If I were yuou, I'd be talking to their technical people right away to get > that problem fixed, because it is a problem. Not for the ISP, and not for their customers, in most cases. This is not a normal case. This is a situation where someone wanted to force an update, but couldn't (initially) get the behavior they expected. Yes, it was an inconvenience for Rodolfo, but that setting saves the ISP a [probably] healthy sum in connectivity costs (in-between carriers). -- Jason Dixon, RHCE DixonGroup Consulting http://www.dixongroup.net -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
