Access Control List
What is Access control list?
Access control list is to filter traffic on entering & out from interface through router. It can be outbound & inbound.
What is outbound and inbound traffic?
Inbound: As traffic comes into an interface.
Inbound ACL:Incoming packets are processed before they route to an outbound interface.
Outbound: Before traffic leaves an interface.
Outbound ACL:Incoming packets are route to the outbound interface then processed.
Any interface can be act as inbound & outbound interface based on traffic comes from & out.
There are generally two types of Access list -a) Standard b) Extended. Another access list also present name as Named access list.
Standard Access list: Filter traffic based on source traffic & permit or deny entire protocol suite.
Extended Access list: Check both source & destination traffic can check specific protocols & port numbers.
Standard ACL Example-1: Block host 10.0.0.3 from gaining access on network 126.96.36.199.
Here routerB is Router1 in above example.
now check from pc-10.0.0.3 that you can access 188.8.131.52 network or not.
Thanks………check next part for examples…..