Unable to Access Update Center URL

Using Jenkins
1

I can’t connect to https://updates.jenkins.io from my network, and this is preventing me from installing and updating Jenkins plugins. I can confirm there is nothing on my end blocking the connection.

root@saturn:~ # ping updates.jenkins.io
PING public.publick8s.jenkins.io (128.24.70.119): 56 data bytes
^C
--- public.publick8s.jenkins.io ping statistics ---
7 packets transmitted, 0 packets received, 100.0% packet loss
root@saturn:~ # fetch -o /dev/null https://updates.jenkins.io
fetch: https://updates.jenkins.io: Operation timed out

If I try from a different network, it works just fine:

root@earth:~ # ping updates.jenkins.io
PING public.publick8s.jenkins.io (128.24.70.119): 56 data bytes
64 bytes from 128.24.70.119: icmp_seq=0 ttl=112 time=39.961 ms
64 bytes from 128.24.70.119: icmp_seq=1 ttl=112 time=39.580 ms
64 bytes from 128.24.70.119: icmp_seq=2 ttl=112 time=39.687 ms
^C
--- public.publick8s.jenkins.io ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 39.580/39.742/39.961/0.160 ms
root@earth:~ # fetch -o /dev/null https://updates.jenkins.io
/dev/null                                             8986  B   40 MBps    00s
2

You have just proven that it is a network issue on your side when you can access it from one network but not the other.
When even a ping is not working you definitely have a firewall that blocks the traffic (local iptable rules?)