nanog mailing list archives
Re: ICMP Blocking Woes
From: Crist Clark <crist.clark () globalstar com>
Date: Tue, 30 Sep 2003 17:22:25 -0700
bdragon () gweep net wrote:
AFAIK, it's been that way since Win95. I recall a certain vendor's dodgy ISDN router * * * on Windows traceroute, but working fine under *ix... for whatever reason, said router didn't like the ICMP traceroute, but returned unreachables in response to UDP when TTL expired. EddyWasn't this based upon the premise that gear should not return ICMP errors as a result of ICMP packet input as a precaution against error loops? ie said dodgy router did the _right_ thing?
That would be disingenious. RFC1122 clearly lists which ICMP are error messages, 3.2.2 Internet Control Message Protocol -- ICMP ICMP messages are grouped into two classes. * ICMP error messages: Destination Unreachable (see Section 3.2.2.1) Redirect (see Section 3.2.2.2) Source Quench (see Section 3.2.2.3) Time Exceeded (see Section 3.2.2.4) Parameter Problem (see Section 3.2.2.5) * ICMP query messages: Echo (see Section 3.2.2.6) Information (see Section 3.2.2.7) Timestamp (see Section 3.2.2.8) Address Mask (see Section 3.2.2.9) But it would not surprise me one bit if some lazy coder actually didn't do what you describe just to make the code simpler and try to use that as a justification. -- Crist J. Clark crist.clark () globalstar com Globalstar Communications (408) 933-4387
Current thread:
- RE: ICMP Blocking Woes, (continued)
- RE: ICMP Blocking Woes Eric Germann (Sep 29)
- RE: ICMP Blocking Woes CA Windon (Sep 29)
- Re: ICMP Blocking Woes Steven M. Bellovin (Sep 29)
- Re: ICMP Blocking Woes Paul Timmins (Sep 29)
- Re: ICMP Blocking Woes E.B. Dreger (Sep 29)
- Re: ICMP Blocking Woes Geo. (Sep 30)
- Re: ICMP Blocking Woes Eric Kagan (Sep 30)
- Re: ICMP Blocking Woes Eric Kagan (Sep 30)
- Re: ICMP Blocking Woes Anthony Cennami (Sep 30)
- RE: ICMP Blocking Woes Eric Germann (Sep 29)
- Re: ICMP Blocking Woes bdragon (Sep 30)
- Re: ICMP Blocking Woes Crist Clark (Sep 30)
- Re: ICMP Blocking Woes John Kristoff (Sep 30)
- Re: ICMP Blocking Woes Crist Clark (Sep 30)
- Re: ICMP Blocking Woes Kevin Oberman (Sep 29)