obfs4 bridges often don't work (maybe MTU?)
Originally created by @emmapeel on #9268 (Redmine)
There have been some reports of obfs4 bridges not working.
A user has found out on the router being used some error messages like:
ICMP 185.xx.xx.xx unreachable - need to frag (mtu 1456), length 556
This is not happenning with other bridges or pluggable transports.
I did some searches online and found out some information regarding MTU and encapsulating that I cannot really follow, like
http://opsmonkey.blogspot.com/2007/02/path-mtu-discovery-and-mtu.html
And in https://ubuntuforums.org/archive/index.php/t-979821.html I found a workaround but the user reports no change after applying it (ifconfig wlan0 mtu 1462)
Do we need to do something about this problem? I think obfs4 bridges need to use bigger packages. Maybe it is a documentation issue, or maybe the configuration should be changed when using obsf4 bridges.
Feature Branch: bugfix/9268-deal-with-smaller-MTU
Related issues
- Related to #12197 (closed)
- Related to #15168 (closed)
- Is duplicate of #15548