Useful CISCO Access Control Lists
These Cisco ACL`s are to block ICMP ping requests from a certain IP address. I developed these experimenting with GNS3. I had two Cisco 3750 routers in GNS3 and I added static IP addresses. 192.168.0.1 for the R1 router and 192.168.0.32 for R2. I then added the ACL lists to R1 and ran the write-memory command and this blocked ICMP ping requests from R2.
access-list 1 deny 192.168.0.32 access-list 101 deny icmp any any
This is the output of the show access-lists command. This is displaying all of the information about my access lists on R1.
R1#show access-lists Standard IP access list 1 10 deny 192.168.0.32 Extended IP access list 101 10 deny icmp any any (15 matches)
This is a useful way to block unwanted access to certain network resources or to limit unwanted network activity.
Here is my arp table.
R1#show arp Protocol Address Age (min) Hardware Addr Type Interface Internet 192.168.0.1 - c201.137c.0000 ARPA FastEthernet0/0 Internet 192.168.0.32 43 c202.0478.0000 ARPA FastEthernet0/0