Basic Firewalling

[elmidwill]

Could someone show me a good example of Access-List to use for a 871 where I would like to get SMTP, port 3489 and a few other ports access to the Internet? I have one working now but I read somewhere that I would need an explicit deny and grant to security reasons?

[ajagadee]

Hi,

Below are some good links that discusses ACL in detail and I have also included an URL on improving security on cisco routers.

Configuring Commonly Used IP ACLs

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080100548.shtml

Configuring IP Access Lists

http://www.cisco.com/en/US/products/sw/secursw/ps1018/products_tech_note09186a00800a5b9a.shtml

Transit Access Control Lists: Filtering at Your Edge

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801afc76.shtml

Improving Security on Cisco Routers

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080120f48.shtml

Let me know if it helps.

Regards,

Arul