I have following network configuration at home:
- Home router installed by my internet provider (ATT) - 2Wire 3600HGV. It also acts as a local nameserver.
- Machine #1, with wired ethernet
- Machine #2, both with wired and wireless ethernet
Previously Machine #1 used dynamic IP configured by systemd dhcpcd@service as described in . Machine #2 previously used NetworkManager applet from GnomeShell and configured as dhcp as well.
Previously I was able to 'ping machine1' but 'ping machine2' has failed. Machine2 name was visible at HomeRouter web page, but was not pingable. That was really odd. I thought that the problem could be because NetworkManager. So I changed both machines to configure its network by netctl. Both machines have similar config:
$ cat /etc/netctl/ethernet Description='A basic dhcp ethernet connection' Interface=enp4s0 Connection=ethernet
Machine 2 uses 'multiple interfaces' configuration as described in .
Also both machines have the same resolv.conf file
$ cat /etc/resolv.conf # Generated by resolvconf domain gateway.2wire.net nameserver 192.168.1.254
Here is network interface information for machine1:
$ ip a ...... 2: enp4s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether bc:5f:f4:32:e0:2d brd ff:ff:ff:ff:ff:ff inet 192.168.1.81/24 brd 192.168.1.255 scope global enp4s0 valid_lft forever preferred_lft forever inet6 fe80::be5f:f4ff:fe32:e02d/64 scope link valid_lft forever preferred_lft forever
and this is for machine2
$ ip a .... 2: enp14s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1f:29:00:19:72 brd ff:ff:ff:ff:ff:ff inet 192.168.1.77/24 brd 192.168.1.255 scope global enp14s0 valid_lft forever preferred_lft forever inet6 fe80::21f:29ff:fe00:1972/64 scope link valid_lft forever preferred_lft forever 3: wls4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:21:5c:5c:06:41 brd ff:ff:ff:ff:ff:ff inet 192.168.1.72/24 brd 192.168.1.255 scope global wls4 valid_lft forever preferred_lft forever inet6 fe80::221:5cff:fe5c:641/64 scope link valid_lft forever preferred_lft forever
So after I changed network config to netctl now machine2 name can be resolved, BUT now I cannot resolve machine1 name!!! I can ping IP address but not the name.
$ ping machine1 ping: unknown host machine1 $ ping 192.168.1.81 PING 192.168.1.81 (192.168.1.81) 56(84) bytes of data. 64 bytes from 192.168.1.81: icmp_seq=1 ttl=64 time=0.130 ms
the same for machine2 works fine
$ ping machine2 PING machine2.gateway.2wire.net (192.168.1.77): 56 data bytes 64 bytes from 192.168.1.77: icmp_seq=0 ttl=64 time=1.761 ms
I can access internet from both machines. Internet works fine, the problem only with name for machine1.
So the question - what the problem can be? How to debug this kind of issues? Is it dhcpcd issue, or router?
Initially router (dns server) did not resolve the machine1 name correctly. It returned error on
$ dig machine1
After some period of time the issue has been resolved "by itself". Now both
$ dig machine1 $ dig machine2
work fine. The case is closed. I do not know what happened but I blame my router.