The impact specifically seems to be traffic between BWRC and EECS. Local traffic within BWRC is not affected. General traffic to/from the Internet does not appear affected. We are unsure about traffic between BWRC and the rest of campus outside EECS.
We will be performing an experimental configuration change tomorrow morning on the related EECS routers to try and alleviate the issue until the true cause can be addressed with IST. An update will be posted here before or around noon.
UPDATE
[2018-08-24 11:24:55 | Derek Calderon]
With help from the campus NOC we have root caused this issue and all symptoms have subsided. The experimental config change scheduled for this morning is no longer necessary, and no further maintenance or outage should be required.
The issue involved a new router which had a too-small interface MTU configured, causing Ethernet frames with a payload >1496 bytes to be dropped. The MTU has now been raised to a more appropriate value.
Please contact help@eecs.berkeley.edu if you continue to experience any network issues.
Resolved as of 2018-08-24 10:36:00