Hi!

In a web server( Server) it may receive millions of request from many users or clients to handle these request whether it will allot an ephemeral port for each and every users???if this is happening whether the client will start communicating through this ephemeral port(whether the client will be intimated about the epheremeal port- no or not) If such epheremal ports are used by the clients whether this will not create any security issues.Can any one make this clear ?????

On the server side, http requests are all received and answered on port 80. You may have several webserver processes/threads listening on that port to handle the numerous requests.

Does this answer your question ?

Hi zeitounator!!

Thanks for replying my query,

Ok so the user load will be balanced by creating number of threads listening to the port number 80 of a webserver.Whether this funda is same for all client and server architecture or it varies ??

It varies depending on the webserver software you use, the way it is configured, the architecture it runs on, the available ressources and the load of the machine. Read your webserver software documentation for this matter.

zeitounator!!!

But in case of normal client and server architecture a server will create an ephimeral port to overcome the load due to client request, so that further the server will start listening to the same port for other client request.Is there any realtime example for this???

I don't understand what an "ephemeral port" is. Webservers usually listen on port 80 (and eventually 443 for https secure connection). I'm not aware of any other port they would listen to, even on an "ephemeral" basis.

Hi zeitounator,


Ephemeral port I meant instead of making all the client to communicate using a single port(the whole process) the server after accepting the client request at port 80,immediately it forks and assign an ephemeral port to that particular client for further communication to take place with that client(Note:This port will be functional till the client is alive).This is in case of normal server and client architecture,but I am trying to find out some real time example for this...

Ok I see, you're talking about openning a random port: there is no such thing for webserver softwares.

This is how, for example, an ftp server works when running in passive mode (making it a nightmare to configure a firewall on the server). But this is not the case for webservers: they use _ONLY_ port 80.

There are a lot of other server software acting the same such as mysql which uses only port 3306, or smtp only port 25, or ssh which uses only port 22 (unless you make tunnels with it) etc... So, opening a random port for further client/server communication is far from being a standard way of functionnning.

Now, there is a random port involved in http communication, but that one is not on the client side. To send each request, the client (browser) will pick a random port (> 2048) and will expect the answer comming on that port. But the request destination port and the answer source port are always port 80. See the http specification for that matter.

Cheers.

Hi zeitounator,

This sounds a very good example/explanation that you had given...

Thanks a lot for your explanation...

Thanks..