gnrc icmpv6: Ping reply goes out the wrong interface #5007
Description
When trying out the new border router setup with ethos in #4725 I found that if I run a ping on my linux machine to the address of the radio interface on the border router the reply is sent out the radio interface instead of sent back through the ethos pipe.
Cloudshark doesn't seem to want to cooperate with me right now so I can't upload the dump, but here's a screenshot of two Wiresharks side by side
The command on the Linux side was simply:
ping6 2001:16d8:ff00:8645:1016:4e54:8bab:4012
Linux net setup:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 fd00:dead:beef::1/128 scope global
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
...
8: sixxs: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1280 qdisc noqueue state UNKNOWN group default qlen 500
link/none
inet6 2001:16d8:ff00:645::2/64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::14d8:ff00:645:2/64 scope link
valid_lft forever preferred_lft forever
139: riot0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 500
link/ether 96:cf:69:cf:73:6e brd ff:ff:ff:ff:ff:ff
inet6 fe80::94cf:69ff:fecf:736e/64 scope link
valid_lft forever preferred_lft forever
inet6 fe80::1/64 scope link
valid_lft forever preferred_lft forever
ip -6 r
2001:16d8:ff00:645::/64 dev sixxs proto kernel metric 256 pref medium
2001:16d8:ff00:8645::/64 via fe80::2 dev riot0 metric 1024 pref medium
unreachable fd00:dead:beef::1 dev lo proto kernel metric 256 error -101 pref medium
fe80::/64 dev docker0 proto kernel metric 256 linkdown pref medium
fe80::/64 dev wlan0 proto kernel metric 256 pref medium
fe80::/64 dev sixxs proto kernel metric 256 pref medium
fe80::/64 dev riot0 proto kernel metric 256 pref medium
default via 2001:16d8:ff00:645::1 dev sixxs metric 1024 pref medium
RIOT border router:
ifconfig
Iface 6 HWaddr: 40:12 Channel: 0 Page: 2 NID: 0x777
Long HWaddr: 12:16:4e:54:8b:ab:40:12
TX-Power: 0dBm State: IDLE max. Retrans.: 3 CSMA Retries: 4
AUTOACK CSMA MTU:1280 HL:64 6LO RTR RTR_ADV IPHC
Source address length: 8
Link type: wireless
inet6 addr: ff02::1/128 scope: local [multicast]
inet6 addr: fe80::1016:4e54:8bab:4012/64 scope: local
inet6 addr: ff02::1:ffab:4012/128 scope: local [multicast]
inet6 addr: 2001:16d8:ff00:8645:1016:4e54:8bab:4012/64 scope: global
inet6 addr: ff02::2/128 scope: local [multicast]
Iface 7 HWaddr: 00:21:d3:60:5a:8d
MTU:1500 HL:64 RTR RTR_ADV
Source address length: 6
Link type: wired
inet6 addr: ff02::1/128 scope: local [multicast]
inet6 addr: fe80::221:d3ff:fe60:5a8d/64 scope: local
inet6 addr: ff02::1:ff60:5a8d/128 scope: local [multicast]
inet6 addr: ff02::2/128 scope: local [multicast]
inet6 addr: fe80::2/64 scope: local
inet6 addr: ff02::1:ff00:2/128 scope: local [multicast]
inet6 addr: 2001:16d8:ff00:8645:221:d3ff:fe60:5a8d/128 scope: global