Re: how to redirect certain IPs to specific url

[Askar Ali Khan <askarali@gmail.com>]

thanks im learn lot of things from your contribution to iptables
mailing lists :)


On Wed, 30 Jun 2004 09:31:16 +0100, Antony Stone
<antony@soft-solutions.co.uk> wrote:
> 
> On Wednesday 30 June 2004 8:44 am, Askar Ali Khan wrote:
> 
> > hi
> > got a very simple question, i want to redirect certain IPs(clients)
> > request to a specific URL (ip)?
> 
> So long as you keep in mind two things:
> 
> 1. An IP address is not the same thing as a URL (firstly, a server on one IP
> address may handle many different domains' websites, secondly a big domain
> such as Amazon, Microsoft, Yahoo may resolve to multiple IP addresses,
> thirdly an IP address (even if unique to a domain) cannot specify a path or
> filename which would follow the first / after the domain in a URL).
> 
> 2. Netfilter works at OSI layers 3/4 (IP addresses and TCP/UDP port numbers),
> whereas HTTP works at layer 7 (URLs, hyperlinks and meaningful content).
> 
> Provided both the above are acceptable, and what you want to do is to redirect
> certain source IP addresses when accessing TCP port 80 to a different
> destination address, then you can do this:
> 
> iptables -A PREROUTING -t nat -p tcp --dport 80 -s a.b.c.d -j DNAT --to
> w.x.y.z

may i have to replace w.x.y.z with the IP of domain or simply
www.abc.com will work?

> 
> where a.b.c.d is the IP address of the client you want to redirect and w.x.y.z
> is where you want them redirected to.   If you want to do it only when they
> try to access a specific destination address (so other destinations are not
> redirected), simply add a "-d p.q.r.s" into the rule above, where p.q.r.s is
> the destination address you want them not to be able to reach.
> 
> If this is not what you want, and you do indeed need to do stuff at OSI layer
> 7, working on HTTP rather than TCP and IP, you should probably look into
> http://www.squid-cache.org

we have firewall it redirect traffic to cache server running "squid"
:) may i put this rule on firewall machine or the cache server ?

> 
> > and also later on how to Flush the specific rule from the the chain as
> > -A will append it on the bottom, how  i will delete it ?
> 
> Repeat the rule but with -D instead of -A
> 
> Regards,
> 
> Antony.
> 
> --
> There's no such thing as bad weather - only the wrong clothes.
> 
>  - Billy Connolly
> 
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