Thanks for your reply. I am afraid that some of your advice goes over my head, but I checked your your link for flushing the DNS cache. Problem:
/etc/rc.d/init.d/nscd restart bash: /etc/rc.d/init.d/nscd: No such file or directory I am running Ubuntu 16.04. -Denis On Sun, Sep 17, 2017 at 12:17 PM, Mike C. <[email protected]> wrote: > On 9/16/17 12:00 PM, [email protected] wrote: > > Where does DNS poisoning occur? Since it was just local to my machine > (no > > general complaints noticed), then something local must have been hacked. > > This could have been either my router or my modem, since my laptop > > connecting via wireless to the router also had the problem. The modem > was > > reset a few times during my contact with Comcast's technician, so it > could > > have been the modem if reset clears the cache. > > > > This whole thing is above my pay grade. Bottom line, if it recurs, what > > should I do to find out what is happening? > > DNS poisoning initially occurs at the DNS server. An untrusted fake name > record is introduced and then is cached in the DNS server and served to > any unwitting entity that makes a DNS A record lookup for a hostname/fqdn. > > This is unlikely to be of a nefarious nature and far more likely to be > caused by crappy code in the airRouter. I did tech. support work for a > local manufacturer of lower-end APs that ran open source based software. > Oh, the DNS & DHCP nightmare problems I could tell you about. > > I did a quick Google on this and found that people experienced similar > problems with the Cisco RV130. If I recall the fix was a config change. > > I don't know if the Comcast modems run a DNS caching server. I doubt it, > but maybe. I've been using a dns caching server on my linux boxen for > many years. Now many linux distros come with dnsmasq installed and it > runs at startup by default. I think modern versions of MS Win also do > this. > > So, what you do if this happens again? Here's what I would do. > > 1. Flush the dns cache on your computer and then try again. Here's how > to do it on all OSs. > https://www.techiecorner.com/35/how-to-flush-dns-cache-in- > linux-windows-mac/ > > 2. If problem persists, plug directly into the modem and try it again. > > 3. If problem persists, edit the /etc/resolv.conf file, add the Google > nameserver addresses and try again. > nameserver 8.8.8.8 > nameserver 8.8.4.4 > > *NOTE: This is only temporary and will be overwritten upon the next DHCP > renewal unless you edit the dhcp config file so that it doesn't request > DNS entries or disable DNS on the Comcast modem. > > 4. If problem still persists, which I suspect is highly unlikely, then > I'd probably start looking at either running some heavy duty malware > software on your pc or wiping it and re-installing the OS from scratch. > > HTH!, > > Mike > > > > _______________________________________________ > PLUG mailing list > [email protected] > http://lists.pdxlinux.org/mailman/listinfo/plug > _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
