[GTALUG] Spamhaus block

Val Kulkov val.kulkov at gmail.com
Fri Feb 22 12:08:34 EST 2019


On Fri, 22 Feb 2019 at 11:58, James Knott via talk <talk at gtalug.org> wrote:

> On 02/22/2019 11:33 AM, Giles Orr wrote:
> > We use this ability a fair bit at my work: the web server determines
> > what name you're looking for from the incoming header,
>
> What would be in the header?  All IP has in the header to differentiate
> connections is IP address and port number.  For example, if I wanted to
> access the Mississauga Library ebook collection, I could open a browser
> to 13.92.99.128 and it would connect to port 443 for https.  I have not
> provided any other information.  So, how would the appropriate server be
> accessed from that, when multiple servers share a single IP?
>

Since HTTP 1.1, a request may contain the "Host" header:
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Host which web
servers can they use to serve proper content for a given host name. See,
for example, http://nginx.org/en/docs/http/request_processing.html for
information how nginx deals with multiple servers on the same IP address.

For https, there is SNI:
https://en.wikipedia.org/wiki/Server_Name_Indication
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gtalug.org/pipermail/talk/attachments/20190222/9937900a/attachment.html>


More information about the talk mailing list