On Fri, 29 Aug 2003, Sanjeev "Ghane" Gupta wrote:
> On Friday, August 29, 2003 9:34 PM [GMT+0800], > Yashpal Nagar <[EMAIL PROTECTED]> wrote: > > > Does anyone have precompiled list of server IPs or any info > > regarding blocking of yahoo messenger & msn messenger. > > In my experience, the best way is to tell users not to use it. Technical > means do not work, you are wasting your time, as Yahoo switches servers > around. > > "Tech" means could work, if you made sure you hired stupid users, of course. > > Either you own the network, in which case you can set, and enforce, an > "Acceptable Use Policy", or you don't, and you shouldn't be interfering with > traffic. As we all (including you, sir) know, this Controlling by Fiat works only with certain kinds of users or environments. Whether the user will listen to you depends on what the user believes will happen to _him_ if he is found disobeying your fiat. Therefore, this approach does not work if the "user" outranks the sysadm in a corporate environment, or in an academic environment where students have never been known to be forced to repeat a year because they used MSN Messenger. (Sad, this last bit.) Therefore, Acceptable Use Policies (AUP), like all other administrative policies, should acquire teeth as much as possible, to deter users from ignoring the policies. Otherwise, it may be better to have no policies at all. Of course, if no automated technical mechanisms can be devised to prevent (or even detect post-facto) these policy infractions, then you have no choice but to depend on Fiat alone. Coming to these messenger things, some of them can be blocked by blocking the protocol. If I remember correctly, guys in our team have done it at certain client sites in the past. I believe Yahoo Messenger is harder to block because it runs on HTTP, and looks indistinguishable from other HTTP traffic. This information is a few years old, though. I remember one major corporate network which was complaining that "Web browsing is terribly slow." We looked. And we found Yahoo Messenger. We also found that the damn Messenger client actually _polls_ the server at a steady frequency, even when no new information is present... it's purely a server-side HTTP based implementation, with the client initiating a query each time. This made Yahoo Messenger the only one which could work through most corporate firewalls (everyone allows HTTP) but also the most inefficient IM service in terms of bandwidth utilisation. Is my understanding of Yahoo Messenger correct? Please confirm/deny. Shuvam _______________________________________________ ilugd mailing list [EMAIL PROTECTED] http://frodo.hserus.net/mailman/listinfo/ilugd
