ACL configure

[azerty800e]

Hello,

I want to create an ACL on Cisco to prevent one network from communicating with others except for the internet. I managed to block the communication, but I lost internet access. I think I'm missing something.

List of my networks:

Network 1: 192.168.1.0/24 Network 2: 192.168.2.0/24 Network 3: 192.168.3.0/24 Network 4: 192.168.4.0/24 Network 5: 192.168.5.0/24 (connected to another router that connects to the internet)

Network 1 should not be able to communicate with other networks except for Network 5.

Can you help me with the commands? Should I use a standard ACL or an extended one?

Thank you for your assistance.

[MHM Cisco World]

You need extended acl

The order is important 

1-Deny ip your subnet to connect to other subnet 

2-Permit ip any any

If there is server in other subnet use permit l4 port (l4 port server use)

MHM

[azerty800e]

Thank for reply, Can't I do a deny any at the end ?

permy any is ok, but i would like make deny any. Possible ?

[MHM Cisco World · Accepted solution]

There are two

Approach 

1- start acl with deny and end it with permit any any 

2-start with petmit and end with deny any any 

Here you mention you want to prevent your network to connect to other subnet and all access to internet 

So it first deny your subnet to connect to other subnet then permit any any (since we dont know which IP the host will connect).

MHM

[balaji.bandi]

What device is this and what code running, depends on the device you need apply IN and OUT where the traffic orginnatic from or leaving to.

check below document with example :

https://community.cisco.com/t5/networking-knowledge-base/cisco-access-control-lists-acl/ta-p/4182349

https://www.ciscopress.com/articles/article.asp?p=1697887