On Sat, 26 Oct 2019 12:27:54 +0100 mick crane <mick.cr...@gmail.com> wrote:
> On 2019-10-26 12:19, Joe wrote: > > On Sat, 26 Oct 2019 11:57:19 +0100 > > mick crane <mick.cr...@gmail.com> wrote: > > > >> hello, > >> what tests can I do to find out what is happening with internet > >> connection ? > >> I have pfsense as router connecting to ISP's broadband box. > >> I think pfsense does that DHCP but also I might have names to > >> ipadresses in host files but just for local network addresses. > >> I have debian apache on local network offering a page with links > >> like my bookmarks > >> > >> Problem is there is one site that sometimes it loads sometimes it > >> times out. > > > > That has something of the sound of DNS, though bear in mind that > > some sites do drop out/get busy for a few seconds. I've known > > Firefox to tell me that it can't find Google, and an immediate > > retry works. > >> I connect from windows-> apache web page of links-> internet site. > >> I've run wireshark in the past but have no idea what to make of the > >> results. > >> > >> What can I run and where to see where is not working ? If is me or > >> them. > > > > Start with DNS. What DNS does the workstation use? Try something > > different. If it's using your router or ISP, try OpenDNS or > > something else outside the ISP's network. > > > > Also try traceroute to the offending site at various times to see if > > you get a consistent time or whether there is a blockage somewhere. > > > > As you say, Wireshark can be difficult, though it has very powerful > > filtering once you know what you're looking for. Again look for > > TCP/53 outgoing and replies. > > > > A simpler alternative for some jobs can be the firewall. I'm still > > on iptables, and if I'm having trouble with a particular type of > > packet, I'll make (or more likely, reenable) a couple of logging > > rules to give me at least a basic understanding of what is going in > > and out. > > I changed the DNS servers on the pfsense from the ISPs to 1.1.1.1, > 1.0.0.1 and make no difference. > What confuses me is how wireshark on one PC with one network card can > capture traffic on network card on another PC > > Naughty promiscuous mode, though I think you have to be root to do that. https://en.wikipedia.org/wiki/Promiscuous_mode -- Joe
