Re: Authoritative Resources for Public DNS Pinging

[Mike Hammett <nanog () ics-il net>]

What irked me today was an equipment manufacturer. I found out because Google had some issues handling ICMP to their 
DNS resolvers today and some of my devices started spazzing out. 


There's no reason this manufacturer doesn't just setup a variety their own servers to handle this, other than being 
lazy. 




----- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

----- Original Message -----

From: "Mark Delany" <k3f () november emu st> 
To: "NANOG" <nanog () nanog org> 
Sent: Tuesday, February 8, 2022 5:13:30 PM 
Subject: Re: Authoritative Resources for Public DNS Pinging 

On 08Feb22, Mike Hammett allegedly wrote: 

> Some people need a clue by four and I'm looking to build my collection of them. 

> "Google services, including Google Public DNS, are not designed as ICMP network testing services" 

Hard to disagree with "their network, their rules", but we're talking about an entrenched, 
pervasive, Internet-wide behaviorial issue. 

My guess is that making ping/ICMP less reliable to the extent that it becomes unusable 
wont change fundamental behavior. Rather, it'll make said "pingers" reach for another tool 
that does more or less the same thing with more or less as little extra effort as possible 
on their part. 

And what might such an alternate tool do? My guess is one which SYN/ACKs various popular 
TCP ports (say 22, 25, 80, 443) and maybe sends a well-formed UDP packet to a few popular 
DNS ports (say 53 and 119). Let's call this command "nmap -sn" with a few tweaks, shall 
we? 

After all, it's no big deal to the pinger if their reachability command now exchanges 
10-12 packets with resource intensive destination ports instead of a couple of packets to 
lightweight destinations. I'll bet most pingers will neither know nor care, especially if 
their next-gen ping works more consistently than the old one. 

So. Question. Will making ping/ICMP mostly useless for home-gamers and lazy network admins 
change internet behaviour for the better? Or will it have unintended consequences such as 
an evolutionary adaptation by the tools resulting in yet more unwanted traffic which is 
even harder to eliminate? 


Mark.