Device problem occurs on: Home Hub 5, Linksys EA8300, Linksys WRT32x
Software versions of OpenWrt 21.02-rc3
Steps to reproduce:
Configure pppoe-wan and wwan to your ISPs
Bring up wwan
ping -I wwan0 126.96.36.199
Now bring up wan (pppoe-wan)
ping -I wwan0 188.8.131.52 looses packets in initial pings as follows:
ping -c10 -Iwwan0 184.108.40.206
PING 220.127.116.11 (18.104.22.168): 56 data bytes
64 bytes from 22.214.171.124: seq=4 ttl=113 time=201.142 ms
64 bytes from 126.96.36.199: seq=5 ttl=113 time=41.131 ms
64 bytes from 188.8.131.52: seq=6 ttl=113 time=50.998 ms
64 bytes from 184.108.40.206: seq=7 ttl=113 time=40.956 ms
64 bytes from 220.127.116.11: seq=8 ttl=113 time=50.932 ms
64 bytes from 18.104.22.168: seq=9 ttl=113 time=40.753 ms
--- 22.214.171.124 ping statistics ---
10 packets transmitted, 6 packets received, 40% packet loss
round-trip min/avg/max = 40.753/70.985/201.142 ms
As a consequence wwan gets disabled by mwan3 because the test pings always fail.
If I take down wan (ifdown wan), then ping through wwan0 works normally.
The same configuration was working fine in 19.07 therefore something was changed in 21.02 that causes this issue with the wireless wan network. I am not sure however if this is related to "Wireless Wan", but I do not have a second wan of ethernet type that I can test this issue with.
Excerpt from /etc/config/network relative to the interfaces: