What does Code(0) and Type(8) mean ?

What do those Codes mean ?



svchost.explorer.exe and system are part of Windows and should be made “outgoing only”. See here. As far as the codes not sure. Did you read the help file?


You mean like this ? ???



This is how the things are set on my PC.

No thats not how. Look at my screen shots in that post. Why do you have svchost as a web browser. You dont need all those rules.

Obviously he’s actually controlling the firewall Vettetech.

Wolfseye: it’s Echo Request

Not sure why you use those rules for system. I have system outright blocked, but YMMV.
On svchost, i don’t have CFP in front of me, i can’t remember if it needs FTP.
HTTP (port 80) is for updates i believe.

Thanks Vettetech, I did changed my settings with the ones you posted in the Screenshot. :wink:

Ok good. Anything else? (R)

Unless the firewall implicit allows inbound Echo reply (Type 0, Code 0) and outbound Echo request (Type 8, Code 0), your own ping requests will be dropped. Same goes for “tracert” attempts :slight_smile:

Just for reference, as follows is a listing of the ICMP types and codes

Type Name

0 Echo Reply

1 Unassigned

2 Unassigned

3 Destination Unreachable
0 Net Unreachable
1 Host Unreachable
2 Protocol Unreachable
3 Port Unreachable
4 Fragmentation Needed and Don’t Fragment was Set
5 Source Route Failed
6 Destination Network Unknown
7 Destination Host Unknown
8 Source Host Isolated
9 Communication with Destination Network is
Administratively Prohibited
10 Communication with Destination Host is
Administratively Prohibited
11 Destination Network Unreachable for Type of Service
12 Destination Host Unreachable for Type of Service
13 Communication Administratively Prohibited
14 Host Precedence Violation
15 Precedence cutoff in effect

4 Source Quench

5 Redirect
0 Redirect Datagram for the Network (or subnet)
1 Redirect Datagram for the Host
2 Redirect Datagram for the Type of Service and Network
3 Redirect Datagram for the Type of Service and Host

6 Alternate Host Address

7 Unassigned

8 Echo

9 Router Advertisement

10 Router Selection

11 Time Exceeded
0 Time to Live exceeded in Transit
1 Fragment Reassembly Time Exceeded

12 Parameter Problem
0 Pointer indicates the error
1 Missing a Required Option
2 Bad Length

13 Timestamp

14 Timestamp Reply

15 Information Request

16 Information Reply

17 Address Mask Request

18 Address Mask Reply

19 Reserved (for Security)

20-29 Reserved (for Robustness Experiment)

30 Traceroute

31 Datagram Conversion Error

32 Mobile Host Redirect

33 IPv6 Where-Are-You

34 IPv6 I-Am-Here

35 Mobile Registration Request

36 Mobile Registration Reply

37 Domain Name Request

38 Domain Name Reply


40 Photuris

41-255 Reserved

I think there are a handful of codes I’ve missed, but they are mainly the “0” codes.

Ewen :slight_smile:

Good one Ewen. Should provide enough information for regular use :slight_smile: