How to create access list to stop the 10.x.x.x from communicating with the 172 Network

[acheak9975]

Hi I have a router that is connected to two networks the 10 network is where Internet comes in. The 172 network is my local lan. How do I create an access list to stop the 10 network from communicating with the 172 network?  The 10 network cannot see the 172 network but 172 can see 10. I still need Internet access through the 10 network. Just want to stop all local traffic from crossing. I really need to figure this out as soon as possible. Thank you.

[pieterh]

how-to configure depends on brand/model os version

please specify more detail

look at this document: IOS Zone Based Firewall Step-by-Step Basic Configuration

[acheak9975]

I am using a 2900 series router 2960 switch both are on iOS 15

[Georg Pauwen]

Hello,

the Zone Based Firewall mentioned by 'pieterh' is the right solution. Check if you have any 'zone' config commands:

2900#conf t

2900(config)#zone ?

If that is the case, post your running configuration, so we can help with the details.