On 2/19/15 3:07 PM, Jeremy Chadwick via Outages wrote:
Something weird is going on with Comcast in Los Angeles: small packets appear to be getting discarded with a loss rate of ~6-10% while larger packets (I've tried 1000 and 1200) seem to make it through without any loss. Things like SSH and IMAP+SSL are impacted consistently (particularly during key exchange), while HTTP does not appear to be, so the issue appears to be affecting both TCP and ICMP (have not tested UDP).
Seeing similar things in the San Francisco Bay Area for the last few hours. Certain combinations of IP addresses/ports/protocols/packet sizes completely fail or have > 30% packet loss; changing one of those variables changes the result. This results in neat things like "HTTP from a browser fails, but 'telnet host 80', 'GET / HTTP/1.0' works just fine". Lots of probably similar problems here: https://downdetector.com/status/comcast-xfinity/san-francisco -- Robert L Mathews, Tiger Technologies, http://www.tigertech.net/