The old putatively Chinese curse goes “May you live in interesting times.” And in that sense, interesting is the adjective I’d apply to networking in Window 10 Version 1803 of late. My previous blog post explained my difficulties in resolving a NetBIOS name, only to figure out that it was case-sensitive when it shouldn’t be. Today, I’m discovering that some upgraded systems lose their ability to respond to a PING from the LAN. This took some sleuthing, but I figured out how to bring back PING in Win10 1803.
How to Bring Back PING in Win10 1803
I can’t replicate this on all my upgraded machines. But I have observed that at least two PCs here on the Chez Tittel LAN have lost their ability to respond to PING requests in the wake of the 1803 upgrade. As it happens, PING relies on the ICMP Echo command to do its thing. And sure enough, in investigating the potential causes of a “missing PING response,” firewall settings head that list. On my two affected machines, both running Windows Defender and its firewall, the Inbound rules for File and Printer Sharing (Echo Request) for both ICMPv4-In and ICMPv6-In were not enabled for any profile: Local/Private (what I wanted), Public (left disabled) and Domain (also enabled). Here’s what the resulting set of rules looks like after the change:
I enabled Private and Domain for both IPv4 and IPv6, but left public turned off. A PING response on a Public network is an invitation to attack!
[Click item to see full-sized view.]
If you find yourself in the situation where you can see a local PC using arp or nbtstat, but it won’t respond to a PING, odds are excellent that this fix will help you, too. Keep this in mind as you upgrade to 1803 going forward. By the time your organization or company takes the plunge, it may be moot. But I still believe that forewarned is fore-armed!
More Win10 Network Follies A’Comin…
As I was digging into this issue, I discovered a couple of other interesting networking gotchas. I haven’t had time to tackle them yet, but will do so as soon as I can. Gotcha #1 is that on at least one of my PCs (one running the Insider Preview), IPv6 has gone missing. Gotcha #2 is that my T520 machine (the subject of my previous post) will now happily connect to or ping either “t520” or “T520.” But alas, my X220 Tablet works only as “x220t” not as any of the other possible permutations: “X220t”, “x220T,” or “X220T.” Weird!