Have you got another computer or phone you can try with?

DimitryD:

 

Thanks for weighing in freitasm. Who is this magical sounddude everyone keeps referring to?

 

This: Sounddude.

"Any sufficiently efficacious technical support is indistinguishable from magic."

     -- Albert Lincoln, Leprechaun Hunter

Sounds more a localised issue where something is being filtered.

Can you confirm what DNS servers are you using?
Can you ping portal.office.com? What do you get back?

Chances are there is some filter along the way - either a proxy or DNS in place.

   DNS Servers . . . . . . . . . . . : fd00::3ea6:2fff:fe07:73
                                       2406:e002:6148:9e01:3ea6:2fff:fe07:73
                                       192.168.178.1

>ping portal.office.com

Pinging b-0004.b-msedge.net [2620:1ec:a92::156] with 32 bytes of data:
Reply from 2620:1ec:a92::156: time=41ms
Reply from 2620:1ec:a92::156: time=39ms
Reply from 2620:1ec:a92::156: time=39ms
Reply from 2620:1ec:a92::156: time=40ms

Ping statistics for 2620:1ec:a92::156:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 39ms, Maximum = 41ms, Average = 39ms

DimitryD:

 

   DNS Servers . . . . . . . . . . . : fd00::3ea6:2fff:fe07:73
                                       2406:e002:6148:9e01:3ea6:2fff:fe07:73
                                       192.168.178.1

 

>ping portal.office.com

 

Pinging b-0004.b-msedge.net [2620:1ec:a92::156] with 32 bytes of data:
Reply from 2620:1ec:a92::156: time=41ms
Reply from 2620:1ec:a92::156: time=39ms
Reply from 2620:1ec:a92::156: time=39ms
Reply from 2620:1ec:a92::156: time=40ms

 

Ping statistics for 2620:1ec:a92::156:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 39ms, Maximum = 41ms, Average = 39ms

 

Ok so thats good - you are recieving ICMP requests so you can talk to it.

traceroute portal.office.com

What do you get? Only the first handful of responses.

>tracert portal.office.com

Tracing route to b-0004.b-msedge.net [13.107.6.156]
over a maximum of 30 hops:

  1     1 ms     1 ms     1 ms  fritz.box [192.168.178.1]
  2     4 ms     4 ms     3 ms  65.7.69.111.static.snap.net.nz [111.69.7.65]
  3     7 ms     3 ms     4 ms  default-rdns.vocus.co.nz [101.98.5.213]
  4     5 ms     4 ms     3 ms  default-rdns.vocus.co.nz [101.98.5.212]
  5    14 ms    17 ms    14 ms  ae68-0.ier01.akl30.ntwk.msn.net [104.44.6.112]
  6    13 ms    13 ms    12 ms  vocusgroupnz.ier01.akl30.ntwk.msn.net [104.44.6.113]
  7    42 ms    65 ms    42 ms  ae27-0.icr01.syd23.ntwk.msn.net [104.44.41.215]
  8    44 ms    42 ms    44 ms  ae29-0.syd03-96cbe-1a.ntwk.msn.net [104.44.236.49]
  9     *        *        *     Request timed out.
 10     *        *        *     Request timed out.
 11     *        *        *     Request timed out.
 12     *        *        *     Request timed out.
 13    47 ms    55 ms    43 ms  13.107.6.156

Trace complete.

So this is all showing that connectivity is there traffic is going out OK. You said in your OP that you work intranet page is not loading? Is that a public or inside the network and if so how are you connecting to the network?

DimitryD:

 

   DNS Servers . . . . . . . . . . . : fd00::3ea6:2fff:fe07:73
                                       2406:e002:6148:9e01:3ea6:2fff:fe07:73
                                       192.168.178.1

Try disabling IPv6 and test with IPv4 only

nztim: Some VPN clients play havoc with M365 they reset the LAN Proxy settings causing M365 Apps to just hang on connecting

Only way to fix it is to reset IE settings

No vpn

Have you tried using a VPN as a temporary solution? Something like Cloudflare WARP? 

@nztim: Some VPN clients play havoc with M365 they reset the LAN Proxy settings causing M365 Apps to just hang on connecting

Only way to fix it is to reset IE settings

 

Mentioned multiple times in the first page: no VPN.

What I would do (YMMV):

• checking the external DNS resolvers in use ( https://dnscheck.tools ) wether it only is the two IPv4only or four DNS w/IPv6 you want/have to use. Expect and verify multiple backup DNS resolver addresses from the ISP.
• checking the modem connection to/from ISP (sometimes they do funny things, changing h/w in the field, etc.) - but unlikely since the other stuff is working.

To me it seems to be a DNS issue. Remember: „The culprit is always the DNS!“ 😉