Problems Connecting Laptop To Modem

Polytropon freebsd at
Thu Jun 21 13:17:44 UTC 2018

On Wed, 20 Jun 2018 01:17:22 +0000, B J wrote:
> On 6/19/18, Polytropon <freebsd at> wrote:
> <snip>
> > Try to ping "step by step": first your router by IP, then
> > a public IP address which definitely will answer (for
> > example, and then something that involves name
> > resolution (for example If name
> > resolution is a problem, the ISP's DNS (or the DNS you
> > are using) should be examined (dig / drill).
> I'll try it and see what happens.

I usually suggest using the CLI tools because they tend to
provide you with an exact answer to a specific question,
whereas a web browser just says "cannot open web page" with
no further explanation of what might be wrong. :-)

> >> If it still does not work, set the network configuration to manual.
> >> Check with the router what address range is reserved for manual usage.
> >> If nothing is reserved, reserve a block of 16, 32 or what ever you like
> >> addresses. Enter one of these addresses into your /etc/rc.conf and try
> >> again.
> >
> > It's still not clear (to me) if the router/modem provides DHCP
> > or not. If it doesn't, manual configuration is needed, but if
> > it does provide DHCP, this should be used - and investigated
> > if it doesn't work as expected.
> It appears to as I've got a tower running FreeBSD connected to it.  I've got:
> ifconfig_fxp0="DHCP"
> in /etc/rc.conf and I have no problem connecting to any of the
> websites I regularly look at.

Okay, so we can definitely assume DHCP working. What you
should now try is to manually check if the "DHCP handshake"
does work on this particular machine (as it obviously does
on the other machines). Calling dhclient and having another
xterm / console open with tcpdump should tell you if the
"DHCP handshake" does actually happen. The steps involved
are just a few and can be easily seen in the network traffic
(even with "limited means" such as tcpdump).

Re-check /etc/rc.conf for the required entries. You should
have something like


but of course with the correct values for your network.
DHCP doesn't require more. Maybe remove or rename /etc/resolv.conf
as this file will usually be written during the "DHCP handshake",
just to make sure there aren't any nonsense values in it.

> I swapped the current HD with a spare that I had on hand and installed
> FreeBSD 11, though only the command line interface.
> For some reason, the network card couldn't be configured with that set
> up and I couldn't do it for the wireless card, either.  (The
> modem/router has both Ethernet and Wi-Fi.)

Both NICs should be addressed during "bsdinstall". For the
wireless networking, the "step by step" method is possible
as well (so you can easily find out at which step there is
a problem).

Again, check "pciconf -lv" for both devices and verify that
the correct drivers have picked them up. See "man fxp" (or
whatever driver applies) for a list of chipsets that it
supports. Just to make sure.

Relevant resources:

I was able to get wireless networking up on a probably 10 years
old Lenovo Thinkpad R61i, so "being old" does not qualify a
computer for not participating in wireless network traffic. :-)

> I checked out the Wi-Fi with an IBM ThinkPad that runs an old version
> of openSUSE and I could easily switch between it and Ethernet without
> any problems.  It certainly doesn't look like the modem/router is the
> problem.

Very good - one out, many still in. :-)

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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