On Friday, September 02, 2011 10:24:23 PM Jesse McGraw wrote:
I've recently run into a hard-to-troubleshoot issue where, somewhere out in the greater Internet, someone was silently dropping packets from my company that happened to be marked with DSCP AF21. I'd fully expect others to either ignore these markings or zero them out but just silently dropping them seems unnecessary.
This is broken. They likely aren't remarking their Internet traffic appropriately to avoid having to schedule it internally, and thus, perform some kind of action on it per their QoS strategy. You may consider remarking your traffic one egress to the Internet to 0 (safe bet?), but this may be a platform- specific capability, and can't tell you for sure it will work; needless to say, you might not want to do this anyway :-).
So, how do you guys treat marked packets that come into/through your networks?
We generally remark all ingress IP Transit traffic to 0, both for v4 and v6. This includes traffic from IP Transit customers. In general terms, trying to provide QoS scheduling services to Internet traffic is fairly cumbersome. There are special cases where Internet traffic could be marked to a non-0 value, but these would be controlled situations for interesting business opportunities. Cheers, Mark.