I've just installed Lubuntu 18.04.3 LTS and it's working fine. I can connect to my wifi and browse the internet. In fact, I post here using it. However when I try to do this sudo apt update it gives me a bunch of connect timed out error. Here is the result.
Err:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Could not connect to security.ubuntu.com:80 (2001:67c:1360:8001::21). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1562::19). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1562::16). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1560:8001::11). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1360:8001::17). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1560:8001::14). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (91.189.91.14), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.26), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.173), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.149), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.23), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.174), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.24), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.31), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.24), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.162), connection timed out
Err:2 http://id.archive.ubuntu.com/ubuntu bionic InRelease
Could not connect to id.archive.ubuntu.com:80 (2001:67c:1562::16). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1360:8001::21). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1560:8001::14). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1562::19). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1360:8001::17). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1560:8001::11). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (91.189.91.24), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.23), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.173), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.24), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.149), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.31), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.26), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.162), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.14), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.174), connection timed out
Err:3 http://id.archive.ubuntu.com/ubuntu bionic-updates InRelease
Unable to connect to id.archive.ubuntu.com:http:
Err:4 http://id.archive.ubuntu.com/ubuntu bionic-backports InRelease
Unable to connect to id.archive.ubuntu.com:http:
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: Failed to fetch http://id.archive.ubuntu.com/ubuntu/...onic/InRelease Could not connect to id.archive.ubuntu.com:80 (2001:67c:1562::16). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1360:8001::21). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1560:8001::14). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1562::19). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1360:8001::17). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (2001:67c:1560:8001::11). - connect (101: Network is unreachable) Could not connect to id.archive.ubuntu.com:80 (91.189.91.24), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.23), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.173), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.24), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.149), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.31), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.26), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.162), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.91.14), connection timed out Could not connect to id.archive.ubuntu.com:80 (91.189.88.174), connection timed out
W: Failed to fetch http://id.archive.ubuntu.com/ubuntu/...ates/InRelease Unable to connect to id.archive.ubuntu.com:http:
W: Failed to fetch http://id.archive.ubuntu.com/ubuntu/...orts/InRelease Unable to connect to id.archive.ubuntu.com:http:
W: Failed to fetch http://security.ubuntu.com/ubuntu/di...rity/InRelease Could not connect to security.ubuntu.com:80 (2001:67c:1360:8001::21). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1562::19). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1562::16). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1560:8001::11). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1360:8001::17). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (2001:67c:1560:8001::14). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (91.189.91.14), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.26), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.173), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.149), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.23), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.174), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.24), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.31), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.24), connection timed out Could not connect to security.ubuntu.com:80 (91.189.88.162), connection timed out
W: Some index files failed to download. They have been ignored, or old ones used instead.


I try to ping some of the ip but it seems to be working fine. Here is the result

ping 91.189.88.174

PING 91.189.88.174 (91.189.88.174) 56(84) bytes of data. 64 bytes from 91.189.88.174: icmp_seq=1 ttl=54 time=264 ms
--- 91.189.88.174 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 264.493/264.750/265.008/0.210 ms

I'm not sure what is the problem. Hope I can get some help. Thankyou for reading this long explanation