How do you allow ICMP Echo Requests on a Cisco ASA 55xx Router?

I'm very new to managing Cisco equipment, so bear with me.

I'm configuring a Cisco ASA 5505 router for my office, and I am reasonably competent enough with the console to configure the basics -- our business needs are not extravagant. Our pings are being dropped by the router, however.

How do I configure the router to allow ICMP Echo Requests? Are there other types of ICMP requests that should be allowed? What are the potential downsides of allowing them all?

Solution 1:

Assuming that you haven't change the global_policy policy-map, have an access-group from_outside on interface outside and that you want to allow icmp echo on the outside interface, here is what to type:

policy-map global_policy
 class inspection_default
  inspect icmp
  exit
 exit
access-list from_outside extended permit icmp any any echo

I would only allow echo request on outside interface.
You may also probably want to take a look to the ASDM