Date: Mon, 7 Oct 2019 22:25:27 -0700 From: Doug Hardie <bc979@lafn.org> To: =?utf-8?Q?Morgan_Wesstr=C3=B6m?= <freebsd-database@pp.dyndns.biz> Cc: freebsd-questions@freebsd.org Subject: Re: Intermittent connectivity loss with em(4) Message-ID: <A9E5F776-CACA-4C3D-8A75-D5EC483874FA@mail.sermon-archive.info> In-Reply-To: <eaa4fb4e-308d-ae37-4ede-7901034e6644@pp.dyndns.biz> References: <ba24db9b-6a34-76d4-7c95-4c2e64d0a5a0@pp.dyndns.biz> <94B563F6-55C4-46BC-BD79-5CC2AD86E6C1@mail.sermon-archive.info> <43f0decc-d459-4ded-dc46-c249bc8e24c9@pp.dyndns.biz> <094A1786-98A8-4CEF-A036-5809D9705EC8@mail.sermon-archive.info> <eaa4fb4e-308d-ae37-4ede-7901034e6644@pp.dyndns.biz>
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It sounds like your cable modem is not using NAT for the various = machines, but is using one local address for both. Hence, it depends on = the response to the arp requests which one will receive the packets. In = my experience you have to configure cable modems for the local IP = addresses of the machines on your network. However, I have only dealt = with a couple of cable modem connections. You might want to contact the = internet provider and explain the situation to them. They can probably = identify the cause. -- Doug > On 7 October 2019, at 08:56, Morgan Wesstr=C3=B6m = <freebsd-database@pp.dyndns.biz> wrote: >=20 > On 2019-10-07 05:55, Doug Hardie wrote: >> Forgot to include, I use a lot of bge devices and some rl. However, = I just discovered one of the remote client's computers has 2 em nics. I = am running the ping test now on it. I did find the following in = messages: >> zgrep em /var/log/messages* >> /var/log/messages.6.gz:Sep 29 15:22:33 brain kernel: em0: link state = changed to DOWN >> /var/log/messages.6.gz:Sep 29 17:08:14 brain kernel: em0: link state = changed to UP >> /var/log/messages.6.gz:Sep 29 17:09:46 brain kernel: em0: link state = changed to DOWN >> /var/log/messages.6.gz:Sep 29 17:09:49 brain kernel: em0: link state = changed to UP >> The first outage was a complete outage to that site. I don't know = what caused it or how it got resolved. I never noticed the second one. >> The client has not been really thrilled with this machine. He had a = much better one, but it was too noisy and replaced it. >> Yet another idea: get mtr "my trace route". package mtr-nox11 and = use it to go to google. It is traceroute and ping combined. You can = use -i 60 with it also. >> -- Doug >=20 > Thank you for your suggestions, Doug. My suspicions right now points = to my cable provider. >=20 > I have two identical machines. One of them is always hooked up as my = router/firewall and while that one is in service I'm free to experiment = on the other. > Earlier this year I switched from an ADSL provider to a DOCSIS 3.0 = Cable provider. The ADSL provider used to give me 5 external IPs and I = never had any trouble running both machines simultaneously through the = ADSL modem. My cable provider gives me 4 IPs but this is the first time = I attempt to run both machines simultaneously through the cable modem. >=20 > Tcpdump shows a peculiar behaviour which is why my suspicions now = points to the cable provider. >=20 > While connectivity is established on my test router, tcpdump properly = shows all packets leaving and entering that machine. But as soon as = connectivity is lost, tcpdump suddenly starts showing packets that are = leaving the _other_ machine instead. It only shows the leaving packets = though, not the incoming ones but regardless I believe this behaviour = isn't normal. As soon as connectivity returns on my test machine, = tcpdump once again returns to only show the packets from that machine. > Connectivity is never affected on the main machine when this happens = and at some point I'll have to unplug it and only have the test machine = connected but I have quite a few services running on that machine so = it's painful to disconnect it, even for a short time. > My DOCSIS knowledge is very limited and I have no idea how I can test = for proper functionality of my cable modem. There are very few settings = in it, none that I find relevant to this problem and the logs don't show = any errors so I'm lost for now. >=20 > /Morgan > _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to = "freebsd-questions-unsubscribe@freebsd.org"
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