DNS problems with my laptop

Hi, after upgrading to 16.2 my laptop I have difficulties with opening some web pages. I get the following error ERR_ADDRESS_UNREACHABLE, then after a little they load. Others, like my own domain do not load at all. It is not a problem of browsers, I have installed FF, Chrome, Brave and Iron and it is the same. It is not the connection or router because I try a PC, another laptop and 2 mobiles without problems. Any suggestions?

(Moderator note: Link removed)

Are you using a VPN?

In your Netowrk Connection settings, can you please check your IP version, whether you are on IPv4 or 6. You should be on 4.
You may want to check your Preferred and alternate DNS, as well.

No, I am not on a VPN.
@337harvey with those changes nothing works

this is what I get

enp0s25: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 28:d2:44:32:b8:68 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 20 memory 0xf2500000-f2520000

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10
loop txqueuelen 1000 (Loopback locale)
RX packets 3614 bytes 831753 (831.7 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 3614 bytes 831753 (831.7 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

wlp3s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.86 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::2cbc:b030:dd89:e181 prefixlen 64 scopeid 0x20
ether a4:4e:31:95:ee:90 txqueuelen 1000 (Ethernet)
RX packets 52568 bytes 62122088 (62.1 MB)
RX errors 0 dropped 1167 overruns 0 frame 0
TX packets 22884 bytes 4822496 (4.8 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

this laptop has also windows installed. Under windows I get to my website.
Under Zorin using Tor from Brave I have access to my website too.

Gday @fvoce ,

As they seem to load ( timedelay) try disabling "Hardware Acceleration" in the browser. restart browser & try again.

Added:
Also clear cache & temp files in the browser, old cache may give the same output.

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Will try everything mentioned here. Just to be clear, in the house I have 3 pc/laptops and 2 mobile phones. This happens only with one laptop and only with Zorin. It has also Windows installed and there I have no problems

How is your gateway static IP configured?

https://linuxize.com/post/how-to-configure-static-ip-address-on-ubuntu-20-04/#:~:text=Depending%20on%20the%20interface%20you,on%20the%20“Apply”%20button.

done. no change

If you're running Tor, be sure you've not accidentally configured it to act as an exit node... I used to run a Tor exit node, my WAN IP address was continually being put into blacklists. Luckily, all I had to do was release the IP lease, get a new IP address, and all was good until the same symptoms you described started again.

And check that the MTU on your connection is actually 1500... that can cause no end of troubles if the MTU (Maximum Transmission Unit) used by your ISP is actually lower than that.

https://www.tp-link.com/us/support/faq/190/

ping -M do -s 1500 9.9.9.9
PING 9.9.9.9 (9.9.9.9) 1500(1528) bytes of data.
ping: local error: message too long, mtu=1500
ping: local error: message too long, mtu=1500
ping: local error: message too long, mtu=1500
ping -M do -s 1472 9.9.9.9
PING 9.9.9.9 (9.9.9.9) 1472(1500) bytes of data.
1480 bytes from 9.9.9.9: icmp_seq=1 ttl=53 time=71.9 ms
1480 bytes from 9.9.9.9: icmp_seq=2 ttl=53 time=94.4 ms
1480 bytes from 9.9.9.9: icmp_seq=3 ttl=53 time=117 ms

You can see that it adds 28 bytes... that's normal (it's the packet header). So a command of ping -M do -s 1472 9.9.9.9 is testing an MTU of 1500.

Hit Ctrl-C to stop the ping process.

You can check what your MTU is set to by:

ip -d link list
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0 minmtu 0 maxmtu 0 addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 
2: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DORMANT group default qlen 1000
    link/ether 8a:55:6f:5b:b4:35 brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 256 maxmtu 2304 addrgenmode none numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535

As you can see, my wlo1 connection has MTU 1500.

To permanently change the MTU:

And to narrow down where the error is, try running:

awk '(f==0) { i=1; while ( i<=NF) {n[i] = $i; i++ }; f=1; next} (f==1){ i=2; while ( i<=NF){ printf "%s = %d\n", n[i], $i; i++}; f=0}'  /proc/net/netstat

It'll give an output like this:

Summary

SyncookiesSent = 0
SyncookiesRecv = 0
SyncookiesFailed = 0
EmbryonicRsts = 0
PruneCalled = 0
RcvPruned = 0
OfoPruned = 0
OutOfWindowIcmps = 0
LockDroppedIcmps = 0
ArpFilter = 0
TW = 74
TWRecycled = 0
TWKilled = 0
PAWSActive = 0
PAWSEstab = 0
DelayedACKs = 999
DelayedACKLocked = 1
DelayedACKLost = 71
ListenOverflows = 0
ListenDrops = 0
TCPHPHits = 24874
TCPPureAcks = 3420
TCPHPAcks = 5530
TCPRenoRecovery = 0
TCPSackRecovery = 0
TCPSACKReneging = 0
TCPSACKReorder = 29
TCPRenoReorder = 0
TCPTSReorder = 0
TCPFullUndo = 0
TCPPartialUndo = 0
TCPDSACKUndo = 0
TCPLossUndo = 0
TCPLostRetransmit = 0
TCPRenoFailures = 0
TCPSackFailures = 0
TCPLossFailures = 0
TCPFastRetrans = 0
TCPSlowStartRetrans = 0
TCPTimeouts = 2
TCPLossProbes = 44
TCPLossProbeRecovery = 1
TCPRenoRecoveryFail = 0
TCPSackRecoveryFail = 0
TCPRcvCollapsed = 0
TCPBacklogCoalesce = 0
TCPDSACKOldSent = 71
TCPDSACKOfoSent = 2
TCPDSACKRecv = 39
TCPDSACKOfoRecv = 0
TCPAbortOnData = 59
TCPAbortOnClose = 23
TCPAbortOnMemory = 0
TCPAbortOnTimeout = 0
TCPAbortOnLinger = 0
TCPAbortFailed = 0
TCPMemoryPressures = 0
TCPMemoryPressuresChrono = 0
TCPSACKDiscard = 0
TCPDSACKIgnoredOld = 0
TCPDSACKIgnoredNoUndo = 23
TCPSpuriousRTOs = 0
TCPMD5NotFound = 0
TCPMD5Unexpected = 0
TCPMD5Failure = 0
TCPSackShifted = 0
TCPSackMerged = 0
TCPSackShiftFallback = 28
TCPBacklogDrop = 0
PFMemallocDrop = 0
TCPMinTTLDrop = 0
TCPDeferAcceptDrop = 0
IPReversePathFilter = 1
TCPTimeWaitOverflow = 0
TCPReqQFullDoCookies = 0
TCPReqQFullDrop = 0
TCPRetransFail = 0
TCPRcvCoalesce = 1005
TCPOFOQueue = 783
TCPOFODrop = 0
TCPOFOMerge = 2
TCPChallengeACK = 1
TCPSYNChallenge = 1
TCPFastOpenActive = 0
TCPFastOpenActiveFail = 0
TCPFastOpenPassive = 0
TCPFastOpenPassiveFail = 0
TCPFastOpenListenOverflow = 0
TCPFastOpenCookieReqd = 0
TCPFastOpenBlackhole = 0
TCPSpuriousRtxHostQueues = 0
BusyPollRxPackets = 0
TCPAutoCorking = 752
TCPFromZeroWindowAdv = 0
TCPToZeroWindowAdv = 0
TCPWantZeroWindowAdv = 0
TCPSynRetrans = 2
TCPOrigDataSent = 9039
TCPHystartTrainDetect = 0
TCPHystartTrainCwnd = 0
TCPHystartDelayDetect = 0
TCPHystartDelayCwnd = 0
TCPACKSkippedSynRecv = 0
TCPACKSkippedPAWS = 0
TCPACKSkippedSeq = 0
TCPACKSkippedFinWait2 = 0
TCPACKSkippedTimeWait = 0
TCPACKSkippedChallenge = 0
TCPWinProbe = 0
TCPKeepAlive = 1072
TCPMTUPFail = 0
TCPMTUPSuccess = 0
TCPDelivered = 9363
TCPDeliveredCE = 0
TCPAckCompressed = 448
TCPZeroWindowDrop = 0
TCPRcvQDrop = 0
TCPWqueueTooBig = 0
TCPFastOpenPassiveAltKey = 0
TcpTimeoutRehash = 2
TcpDuplicateDataRehash = 1
TCPDSACKRecvSegs = 39
TCPDSACKIgnoredDubious = 0
TCPMigrateReqSuccess = 0
TCPMigrateReqFailure = 0
InNoRoutes = 0
InTruncatedPkts = 0
InMcastPkts = 651
OutMcastPkts = 477
InBcastPkts = 0
OutBcastPkts = 0
InOctets = 98576549
OutOctets = 5274975
InMcastOctets = 142485
OutMcastOctets = 91852
InBcastOctets = 0
OutBcastOctets = 0
InCsumErrors = 0
InNoECTPkts = 89776
InECT1Pkts = 0
InECT0Pkts = 0
InCEPkts = 0
ReasmOverlaps = 0
MPCapableSYNRX = 0
MPCapableSYNTX = 0
MPCapableSYNACKRX = 0
MPCapableACKRX = 0
MPCapableFallbackACK = 0
MPCapableFallbackSYNACK = 0
MPFallbackTokenInit = 0
MPTCPRetrans = 0
MPJoinNoTokenFound = 0
MPJoinSynRx = 0
MPJoinSynAckRx = 0
MPJoinSynAckHMacFailure = 0
MPJoinAckRx = 0
MPJoinAckHMacFailure = 0
DSSNotMatching = 0
InfiniteMapRx = 0
DSSNoMatchTCP = 0
DataCsumErr = 0
OFOQueueTail = 0
OFOQueue = 0
OFOMerge = 0
NoDSSInWindow = 0
DuplicateData = 0
AddAddr = 0
EchoAdd = 0
PortAdd = 0
AddAddrDrop = 0
MPJoinPortSynRx = 0
MPJoinPortSynAckRx = 0
MPJoinPortAckRx = 0
MismatchPortSynRx = 0
MismatchPortAckRx = 0
RmAddr = 0
RmAddrDrop = 0
RmSubflow = 0
MPPrioTx = 0
MPPrioRx = 0
MPFailTx = 0
MPFailRx = 0
RcvPruned = 0
SubflowStale = 0
SubflowRecover = 0

Thank you all for your suggestions, but I am not so techie with all this stuff and using terminal and all the other things. I will make a backup and then a brand new installation of zorin.

1 Like

Try these commands,

sudo systemd-resolve --flush-caches

sudo resolvectl flush-caches

sudo apt update && sudo apt upgrade

reboot

If no good, please run this command & post here, cover any sensitive info.

tracepath google.com

If still persisting, Open the "systems Monitor"
Watch or screenshot the cpu/ram usage, when you try loading your browser page/s.
Again Post results here please.
When this is done it may help the others.
i'm off to bed.

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