IPv4 address not being assigned on fresh install

bbsarchlinux321 · 2019-02-19 04:51:15

It appears that an IPv4 address is not being assigned on a fresh install of arch linux when trying to connect to the internet (whether it be via ethernet or wifi). The output of `ip addr` shows that the adapter does not have an "inet" address, only "inet6" addresses (whether it be ethernet or wifi, I've confirmed it happens for both). I am connected to the network, and a few websites will load in the browser (like google.com, facebook.com, fast.com, etc...), but most will not (reddit.com, slack.com, etc...) The ones that do not load give the "This site can't be reached" / "dns probe finished nxdomain" error. The `/etc/resolv.conf` file also only has -

nameserver 2001:558:feed::1
nameserver 2001:558:feed::2

Whats strange is that there are multiple other laptops (even ones of the exact same make/model, so they're on literally the exact same hardware) that can connect without any issues on the network. These laptops are also all running arch. All of these laptops have an `inet` address in addition to the `inet6` addresses (noted from `ip addr` output). The other laptops `/etc/resolv.conf` file all have -

search hsd1.in.comcast.net
nameserver 75.75.75.75
nameserver 75.75.76.76
nameserver 2001:558:feed::1
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 2001:558:feed::2

I've tried manually adding the parts of the `/etc/resolv.conf` file that are missing on the fresh install to the `/etc/resolv.conf.head` file. After doing so I confirmed that the generated `/etc/resolv.conf` file did now contain the info that was previously missing, however it doesn't seem to have had any affect on the outcome (still can't connect).

A few other things to note -

- This issue appears to only be with laptops with fresh installs. I have tried installing on two different laptops that are on different hardware, and both had the exact same network issues (not able to connect properly at the office, but able to connect without issues at my home network).
- There are multiple other laptops running arch that were setup months ago (6-12) that are able to connect to the office network and home network without any issues. These laptops never had any special network settings applied, they just used the default antergos install settings.

- `ping google.com` works as expected without any issues (receives packets and no packet loss)
- `ping 8.8.8.8` does not work and errors something like "network is unreachable"

- I've tried both an antergos install and a manual install using a bootable arch live usb, both result in the same exact network issues.

- I have tried restarting all routers and the modem as well as the laptop (multiple times). This seems to have had no effect.
- I have tried hooking the laptop directly into the modem via ethernet cable. This did not change anything.

My best guess at whats wrong at this point is that for some reason the laptops network adapter is not being assigned an IPv4 address, but I don't know why. It appears that the issue is something to do with the office network rather than the laptops setup since the laptop seems to connect without any trouble on my home network. Both networks (office and home) use the same ISP and modem, but different routers (the home one uses the modems built in router, office one has multiple routers setup through the building). Keep in mind that I did try hooking the laptop directly into the office modem via ethernet cable (though there were also 3 other ethernet cables also plugged into the modem at that time that go to routers) and that did not seem to work. If that was the case though (the issue being with the office network rather than the arch install), I don't understand why the other laptops that have been running arch for months are able to connect without any issues. Does anyone have any idea what the issue could be, or what I might do at this point to try and pinpoint the issue?

Last edited by bbsarchlinux321 (2019-02-19 05:13:05)

fukawi2 · 2019-02-19 05:51:16

How have you configured your network? (eg, netctl, networkd etc)
What do the config files for that tool look like?
Is there anything relevant in the logs?

bbsarchlinux321 · 2019-02-19 12:36:48

The network was setup using dhcpcd and ip link. For the ethernet adapter I ran `ip link set enp1s0 up` and then `dhcpcd enp1s0`. The

 /etc/dhcpcd.conf

file is

# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.

# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel

# Inform the DHCP server of our hostname for DDNS.
hostname

# Use the hardware address of the interface for the Client ID.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
# Some non-RFC compliant DHCP servers do not reply with this set.
# In this case, comment out duid and enable clientid above.
duid

# Persist interface configuration when dhcpcd exits.
persistent

# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit

# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Respect the network MTU. This is applied to DHCP routes.
option interface_mtu

# Most distributions have NTP support.
#option ntp_servers

# A ServerID is required by RFC2131.
require dhcp_server_identifier

# Generate SLAAC address using the Hardware Address of the interface
#slaac hwaddr
# OR generate Stable Private IPv6 Addresses based from the DUID
slaac private
noipv4ll

I used

 wifi-menu wlp2s0

to connect the wifi adapter. The generated profile looks like

Description="Automatically generated profile by wifi-menu"
interface=wlp2s0
Connection=wireless
Security=wpa
ESSID=network_name
IP=dhcp
Key=network_key

Are there specific log files I should check? I checked

 journalctl -u dhcpcd

and nothing appeared to be obviously wrong. Are there other log files I should check? I can put the output here if needed.

seth · 2019-02-19 13:32:06

Try "dhcpcd -4 …" to enforce IPv4 only, see the resulting error messages. This is very likely related to the dhcp server.
Ftr, the modem has probably (maybe) a MAC filter for known devices, ie. you'll not get any connection at all on direct connections (unless you spoof your MAC)

bbsarchlinux321 · 2019-02-19 18:24:55

Thanks for the suggestion, Seth. I ended up resolving the issue earlier today. It turned out to be an issue with the modem. I'm not sure exactly what about the modem was faulty, but when I replaced it with a new modem of the same make/model everything worked properly as expected.

fukawi2 · 2019-02-19 22:18:22

bbsarchlinux321 wrote:

I can put the output here if needed.

For future reference, yes post the output since we can't see it otherwise and we're not psychics.

Arch Linux

#1 2019-02-19 04:51:15

IPv4 address not being assigned on fresh install

#2 2019-02-19 05:51:16

Re: IPv4 address not being assigned on fresh install

#3 2019-02-19 12:36:48

Re: IPv4 address not being assigned on fresh install

#4 2019-02-19 13:32:06

Re: IPv4 address not being assigned on fresh install

#5 2019-02-19 18:24:55

Re: IPv4 address not being assigned on fresh install

#6 2019-02-19 22:18:22

Re: IPv4 address not being assigned on fresh install

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