Block Traffic from Specific IP

Unanswered Question
Nov 6th, 2007
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I have a Cisco 871 Router and I have it configured with the following IP range.

Cisco IP:



The Clients use this settings

IP: thru


I have a Wireless router whose WAN IP is and LAN is set to network. I want any device connected on the network to not be able to access my 10. network.

How can I configure my Cisco to accomplish this?



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intelide3 Tue, 11/06/2007 - 16:09
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if you dont need any other network connectivity then just dont add a default gateway for network.


mskhalsa Tue, 11/06/2007 - 16:33
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I can do that but I also should mention that I do want network to be able to access the WAN (through the 10. network).


I am trying to do this with ACL but apparently I am not entering the correct settings.

I have this

access-list 100 deny tcp log


intelide3 Wed, 11/07/2007 - 22:11
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first we need to be clear whether wireless router perform NAT or routing.

by performing NAT(PAT) your 192.168.0 subnet will look like 10. ip - so cant be block entering 10.0 subnet (or the switch).

by routing : if that 192.168.0 subnet does not use a default gateway (ip 10.x.x.x the wireless router) for that subnet - you will not be able to go to 10. network - hence you cant reach the internet.

you cant block the wireless 10.x.x.x ip itself entering your 10. subnet switch - but you can block it entering internet using basic standard extended ACL.


pls rate :)

mskhalsa Fri, 11/09/2007 - 09:04
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Yes my router is setup to use NAT and though I am understanding most of what you are saying I am still looking for a viable option even if that means I have to get away from NAT and go to Routing.

Basically 192.x.x.x network should only be able to access the internet using the as its gateway but still be blocked from everything else on the 10.10.10.x network.

I am confused on how to achieve this but if its not possible then I guess I will still survive!




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