Access List Question

[Danno]

If there are no access lists applied at all on a Cisco router (i.e my 3800 - 12.4), does that imply a permit any any? Basically, without access lists does it just route everything? I believe that's the case but I'd just like confirmation.

What I'm getting at is that if I'd like to just block one thing (or a couple things) and make my access list as follows:

access-list 101 deny icmp any any timestamp-request log
access-list 101 permit any any
(then apply it to my outside int.)
ip access-group 101 in

does this allow everything to run as it currently does with no access lists except for that it's now denying icmp timestamp requests?

Thanks for any help!

[Planet]

the access list is for ipsec including vpn, no access list, no ipsec.Check out the Cisco IOS Security Configuration Guide for more information: http://www.cisco.com/en/US/partner/products/ps6441/products_configuration_guide_book09186a008049e249. html

[Danno]

There's currently no access-lists at all. I want to apply one like I mentioned above but want to make sure I'm not causing any issues. There's no vpn involved.

I just wanted to know what the default behaviour is when there's no access-list applied to an interface. Thanks.