Summary

Users at the main building on the main campus reported that they are unable to access forms.office.com (13.107.6.194) from their desktop/ laptop devices while connected via wired. On my initial troubleshooting, I quickly ruled out that it is a L1 issue by checking the tdr cable-diagnostic on the user's device and swapping out the Ethernet cable. I also ruled out L2 by taking of all ISE commands and just had the user's device connected to a regular switchport on the data vlan. Finally checking the Firewall to verify that it is not blocking any traffic to the Microsoft (which it shouldn't since there are a lot of Microsoft services in the enterprise environment).

Pinging to forms.office.com (13.107.6.194) from user's device:

Pinging to forms.office.com from a different network:

From the initial troubleshooting, it was puzzling to see that all the checks passed and that there were no restrictions or limitations that I could identified that could resolve the issue. Finally, a hardware refresh was in place for the user and once they received a new device then the issue resolved itself. I initially thought that there were something weird on the Windows native Firewall that was blocking the traffic to forms.office.com that was resolved with a new device.

However, towards the end of 2023, the same user reported that they could no longer access forms.office.com once again. This time around I took a different approach to resolving the issue. I quickly compared the topology Distribution and Access layer of the main building to another building that has a similar topology. The topologies are the same with the same type of family of switches for the Distribution layer and the Access layer. Yet, the main building Distribution switch could not ping forms.office.com on any of its' gateways compared to the secondary building Distribution switch.

Pinging to forms.office.com from the affected Distribution stack:

Pinging to forms.office.com from a working Distribution stack:

I made the recommendation to my team that we should upgrade and reboot the affected distribution. The recommendation was accepted and I proceeded with the upgrade. After the upgrade, I confirmed that the Distribution stack was able to source pings out of its' gateways to forms.office.com and that the user was able to resolve the webpage to continue their work.