NethServer Version: 7.5.1804 (final)
Module:
I’ve been having issues with Internet browsing through Squid (way before posting this issue, so I think is not related), from connection timeout in clients browsers (Firefox mostly), to slow pages rendering and proxy error form client browser.
I believe this issue might be related to DNS resolution, DNS response taking to long or Squid trying to use IPv6 and then changing to IPv4.
Is there a way to check this for sure?
Maybe there’s some info about the error in the squid logfiles?
You may check the DNS with nslookup nethserver.org or in web UI diagnostics panel.
Ok so after checking squid cache log (I might need help for finding error or anything wrong on access log 
) I found this repeating over and over.
kid1| ipcacheParse: No Address records in response to '...'
This goes for a lot of sites, I’m putting here a piece of cache log. A quick google search tells me this might be related to DNS issues, but I’m clueless of what to do next.
If possible, I’d check the logs of the DNS server.
Or use tcpdump to sniff traffic to/from the DNS.
Or use a different DNS.
@filippo_carletti thanks for helping out.
Where are this logs, I checked /var/log/* and found no trace of dnsmasq logs, I currently have my gateway/proxy NS7 pointing to the following DNS servers:
200.55.128.3
200.55.128.4
169.158.128.136
8.8.8.8
I’d leave only one of them, let’s start with 8.8.8.8, which is used by a lot of people and never gave problems.
So, I did two things:
config set dns configuration NameServers 8.8.8.8
signal-event nethserver-dnsmasq-save
I did this yesterday on so far no one has complained again, should thing keeps like this, this week I will put this as solved.
BTW, I have a question, while using proxy, who actually ask for URL DNS resolution? Is it the client PC or the proxy service?