AT&T hybrid router: Internet priority and ping issues
in IT Support ·
Jack Cook7 said:Check this outI'm hitting a wall here—whenever I run ping -l 1434 google.com, I get hit with multiple timeouts in a row.
If I try ping -f -l 1434 google.com, I'm seeing 3 losses on one go, and then 4 losses for the next 5 attempts.
But if I drop it down to ping -f -l 1432 google.com, everything works perfectly fine.
That right there? That's where your packets are getting shredded. You're basically hitting a ceiling between 1432 and 1434 bytes for the IP packet size at Layer 3. Just remember, the actual Layer 2 frame is always going to be a bit beefier because of all that extra IP overhead.
And honestly, Google.com doesn't matter here—it’s not affecting your actual performance. These jumbo frame limitations usually pop up on local networks since you're running on an Ethernet setup. A frame size can't just sail right through a router if it's too big.
Try using a ping with the -f flag to hunt down the absolute max IP packet size you can push to your specific game server.
Also, do some digging to find the average packet size your game app is actually spitting out. It’s probably buried in one of those endless readme.txt files that nobody ever bothers to read.
I couldn't find anything useful in the app texts or logs besides total transmitted packets, overhead, and stuff like that, so I just grabbed a Wireshark capture of some gameplay. Ping was steady at 42-43.
Basically, most of the packets (UDP) range from 57 bytes on the wire (15 bytes of data) to 72 bytes on the wire (30 bytes of data), making up about 70% of the traffic. Then, from 73 bytes on the wire (31 data) up to 212 on the wire (170 data), that’s another 20%. The remaining 10% are the outliers, ranging from 218 on the wire (176 data) up to 789 on the wire (747 data).
The absolute max I captured was 909 bytes on the wire, which is 867 bytes of data.
Sent you the log via DM.