[ edit ] My other devices can ping my personal computer, but my personal computer can not ping any other device including the router to which my personal computer is attached immediately .

I would check for a conflicting IP address on another device .
( flush though I am not sure your ping results are reproducible with this. It does not quite fit my intuition about ARP, and unfortunately I did not find any similar combination in Google Search results. possibly there is an extra problem or a different problem. But it is a nice thing to check, and it might help you find some clue ) .
On your personal computer, find what the MAC address ( “ hardware savoir-faire ” ) is. If you run ip link show dev eth1, the MAC address is the measure shown after link/ether.

On one of the other devices, check cautiously what MAC address it has cached for your IP, If the other device runs Linux, you can check the ARP hoard using ip -4 neigh. If the other device runs Windows, you can check the ARP cache using arp -a ( in Windows command lineage ). If it shows a unlike MAC address for your IP, then you were actually pinging a different device, not your personal computer : – ) .
former version :

What can be the probable reason behind not able to ping?

AfroJoe : therefore many reasons

technically, ping showing “ Destination Host Unreachable ” is a quite specific mistake message ! Your output about surely means the ARP resoluteness is failing. On It looked like this was the lapp calculator you ran ping on, and you confirmed that in a late edit. In that sheath, hera is how you confirm an ARP offspring :

$ ping
PING ( 56(84) bytes of data.
From icmp_seq=1 Destination Host Unreachable
From icmp_seq=2 Destination Host Unreachable
From icmp_seq=3 Destination Host Unreachable
--- ping statistics ---
4 packets transmitted, 0 received, +3 errors, 100% packet loss, time 3050ms
pipe 4

$ ip -4 neigh dev wlp2s0 lladdr 74:44:01:86:42:d6 REACHABLE dev wlp2s0  INCOMPLETE

successful ARP resolving power involves an exchange like this :

$ sudo tcpdump -n -i wlp2s0 arp or icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlp2s0, link-type EN10MB (Ethernet), capture size 262144 bytes
13:43:49.469349 ARP, Request who-has tell, length 28
13:43:49.470046 ARP, Reply is-at 74:44:01:86:42:d6, length 28
13:43:49.852608 IP > ICMP echo request, id 5246, seq 21, length 64
13:43:49.854600 IP > ICMP echo reply, id 5246, seq 21, length 64
13:43:50.853879 IP > ICMP echo request, id 5246, seq 22, length 64
13:43:50.855867 IP > ICMP echo reply, id 5246, seq 22, length 64
18 packets captured
18 packets received by filter
0 packets dropped by kernel

( observed while running ping, and forcing an ARP refresh using ip neigh flush dev wlp2s0 ).

note : this rendition basically alone applies to ping. It does not apply when you get a “ Host Unreachable ” message from a “ convention ” TCP/IP application like ssh or curl, because that might besides mean you received an ICMP error reply such as “ administratively prohibited ” ( from a firewall ). however ping receives and decodes the entire ICMP answer. So ping would tell you that the mistake was specifically “ administratively prohibited ”, not fair “ Host unapproachable ” .
besides, this Q & A is about IPv4. I have not checked how it could be adapted for IPv6 .

Why does ARP resolution fail?

AfroJoe : sol many reasons

I have one other piece of unavowed cognition. Unless your Ubuntu customer organization was measuredly configured by person, the address was assigned through an exchange of DHCP packets. typically this exchange would involve the router, although in early cases it might only involve a Windows Server or other type of server. In this lawsuit where the router is the DHCP server or relay, your system was already able to exchange some packets with the router .
You can test re-triggering the DHCP central by breaking and re-making the connection. [ * ] Of course if the problem keeps coming back again “ randomly ”, doing this does not solve the underlying problem, and you might want to investigate the joining while it is still broken .
( [ * ] Apple wrote an optimization which can do the DHCP central after an commute of specific ARP packets. possibly there are new quirks with this, but I have not seen it used on Linux however. )

It is common to see this error with a connection using DHCP and WiFi, when the radio bespeak is lost at some target. ( And you catch it before the wireless layer had given up entirely … I ‘m not surely why I ‘ve seen that thus many times, possibly I was observing buggy or badly written systems ). But eth1 is not a wireless local area network connection .
I believe that DHCP for IPv4 operates without requiring any ARP. At least in the initial DHCP exchange .

Remaining possibilities

From the facts in the initial version of your motion I struggled to think of any individual scenario which is peculiarly common. ( Including my implicit assumptions. It ‘s improbable that person would post this wonder without trying to plug their calculator in to an operational router ) .

  • The network you’re connected to has no device with the address If that’s what gave you a DHCP address, then it was removed from the network. Unplugged, or just died.
  • You configured eth1 manually AND one of
    • you’re not using NetworkManager in Ubuntu Desktop, and
      • you don’t actually have an ethernet link detected (check ethtool).
      • Or you have an ethernet link detected, but the switch requires you to provide a password or other authentication using 802.1X.
      • Or you have an ethernet link detected, but you’re required to register your computer’s MAC address with the network administrator.
    • you have a cable that works just well enough to detect a link, but not enough to reliably carry data packets.

Leave a Reply

Your email address will not be published.