Here,we are going to see how to configure standard access list for multiple networks.

Step 1:Create a topology like this, and configure ip address like in topology that i have given.In packet tracer, router having only two fastethernet. So, we have to add interface depends on our requirements.Go to this link to learn how to add interfaces.

How to add more interfaces to router?

Step 2:Now,I am going to stop entire network ,packets that is going to network.And a host to network.Other host in network should communicate with server that is network.

Step 3:First we should choose right interfaces for this access list to bind.Interface fastethernet2/0 is the right interface for this access list,because packets from both network will be going out through fastethenet2/0.

Step 4:Now,create standard access list based on above statement,deny statement must be at top of the access list, because router process access list from top to bottom.So, We must configure deny line first after that we configure permit.

In Router ,Global Configuration mode,

Router(config)#access-list 10 deny
Router(config)#access-list 10 deny host
Router(config)#access-list 10 permit any

       Here,Router will process first line and it will block packets from network to network.

       Second line will block the host only,

       Packets from other than will not match above two statements then the router will process third line 'permit any' statement allow rest of the ip address other that the match found in access list the router wont go to the next line.Network can communicate with network

Step 5:Go to router and bind the access list to fastethernet 2/0,

Router(config)#interface fastethernet2/0
Router(config-if)#ip access-group 10 out

     Here, 'Out' This tells the router packet that goes out of this interface fastethernet 2/0 will be filtered based on access list 10.

Step 6:Now, I am going to check with  host from network and host from network.

Here,entire network were blocked and host from was blocked.other host still communicating with server.

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