Based on further testing it seems like AWS expects ICMP rules to be
defined as type..-1. Strangely the new AWS CLI tools do not allow
passing in a negative value, while the AWS web console always generates
rules that are interpreted by fog as type..-1. Looking at other icmp
types like 3 - destination unreachable I think the from and to ports may
actually be interpreted by AWS as type and code respectively. It still
seems strange to me that AWS would specify the code for echo
request/reply as -1, since according to
http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol the code
should be 0 in both cases. However, using -1 seems best since that is
what works and what the web-ui generates. Upon further reflection -1 is
probably just a null placeholder value.