A potential fix for login and save problems

(Paul McCombes) #1

If you are having problems logging on, saving rides, losing rider details, taking ages to change bike configuration (e.g. wheels) (as I was) then there may be a fixable problem with your network settings.

(This is for windows - tested on 7 and 10)

How to test it

Type this command at the command prompt

  netsh interface ipv4 show subinterfaces

MTU     MediaSenseState Bytes In Bytes Out Interface
------  --------------- --------- --------- -------------
<bignum> 1 <num> <num>     Loopback Pseudo-Interface 1
_1500    1 <num> <num>     Wireless Network Connection 2 _

(Note the name in _ bold italics _ - you’ll need it later)The default MTU is 1500 - subtract 28 to get 1472.

Type this command (if yor MTU is different then subtract28 and use that numbers as well after the -l

ping -f -l 1472 -n 1 -w 100

Pinging with 1472 bytes of data:
Packet needs to be fragmented but DF set.

If you get the “Packet needs to be fragmented” message back then your problem is the MTU setting.

How to change it

First find the maximum MTU by running

ping -f -l 1471 -n 1 -w 100

but decrease the -l value by 1 each time. Eventually you will see something like

Pinging with 1464 bytes of data:
Reply from bytes=1464 time=16ms TTL=252

Although your value may vary. Take the 1464 (in this case) and add 28 to get 1492.

Then run

netsh interface ipv4 set subinterface “Wireless Network Connection 2” mtu=1492 store=persistent

(The name is quotes is the name of the interface from the first netsh command.)

And enjoy Zwift actually working.