i’ve been having issues when connected to my local wifi at home, with my android facebook app (as well as fb messenger) not loading profile pictures. it would work fine when connected to my cellular network, or even the wifi at work. but for some reason, it wasn’t working at home.

after doing some digging around with logcat on my phone, it appeared to be a problem with resolving the domain name “fbcdn-profile-a.akamaihd.net”. when i ran the host command i got the following:

[smorks@miked ~]$ host fbcdn-profile-a.akamaihd.net pi
;; Truncated, retrying in TCP mode.
... rest of host output ...

it appeared to work fine when run with the dig command. after some googling of the above error message, i found talk of the minimal-responses yes; option for bind. i added it to my config file, and everything started working as expected on my phone.

my guess would be is that the host command was using a smaller buffer than the dig command, which is why it was saying that is was “Truncated”. i’m assuming that either the facebook app or the network stack used in android was using a small buffer as well but not retrying with TCP mode.