Generally speaking there's really not a lot to gain from a security perspective by blocking ICMP replies, so if that's your main motivation it's probably more worthwhile to focus on other areas.
To answer your question, ICMPv4 Echo Reply has a Type of 0 (RFC 792), and the corresponding ICMPv6 Type is 129 (RFC 4443). In theory you should be able to allow inbound ICMP Echo requests and block these specific types of outbound traffic, but doing so has no discernible effect when I try it on a Windows Server 2012 R2 VM.
As Mikael suggested, it is possible to create a rule which blocks outbound ICMP Echo Replies. Steps below.
However the rule has no discernible effect on the Echo Replies sent by Windows. It appears to only block Echo Replies originating from programs running in User Space.
Generally speaking there's really not a lot to gain from a security perspective by blocking ICMP replies, so if that's your main motivation it's probably more worthwhile to focus on other areas.
To answer your question, ICMPv4 Echo Reply has a
Typeof0(RFC 792), and the corresponding ICMPv6Typeis129(RFC 4443). In theory you should be able to allow inbound ICMP Echo requests and block these specific types of outbound traffic, but doing so has no discernible effect when I try it on a Windows Server 2012 R2 VM.As Mikael suggested, it is possible to create a rule which blocks outbound ICMP Echo Replies. Steps below.
However the rule has no discernible effect on the Echo Replies sent by Windows. It appears to only block Echo Replies originating from programs running in User Space.