Cisco ACL Builder turns an action, protocol, source, destination and optional destination port into one Cisco IOS extended access-list entry, in syntax you can paste onto a device. A number in the ACL field gives a numbered access-list line; a name gives an ip access-list extended block.

How to read the result

The output is the entry plus an example of applying the ACL inbound on an interface (ip access-group), which you adjust to the real interface. Build one entry per run and put them in order yourself: IOS evaluates ACL entries top to bottom and stops at the first match. Source and destination take any, host 10.0.0.1 or an address with a wildcard mask; the port is added as eq <port> for TCP and UDP only.

Defender tips

End every ACL with an explicit deny and a log keyword rather than relying on the implicit deny at the end; an explicit, logged deny tells you exactly what is being blocked instead of leaving it invisible.
Order entries most-specific first; a broad permit or deny placed early can shadow a more specific rule listed after it, since only the first match is applied.
Remember Cisco ACLs use wildcard masks, the inverse of a subnet mask; the CIDR Notation Converter shows both forms side by side if you need to translate one to the other.

FAQ

What is the difference between a standard and an extended ACL?

A standard ACL filters on source address only; an extended ACL can match source and destination address, protocol and port, which is what most modern rule sets need.

Does this push the configuration to a device?

No. It only generates the text; you review and apply it yourself, which is deliberate, since this tool has no access to any device.

Does it support IPv6 ACLs?

No. It builds IPv4 extended entries only. IPv6 ACLs use the named ipv6 access-list syntax, which this tool does not generate.