If there is more than one interface, print the id of the receiving
interface for convenience.
```
ping6 ff02::1
2020-02-20 18:19:38,644 # 12 bytes from fe80::d0ae:c1b:2054:58e%7: icmp_seq=0 ttl=64 rssi=-45 dBm time=4.801 ms
2020-02-20 18:19:38,652 # 12 bytes from fe80::d0ae:c1b:2054:58c%8: icmp_seq=0 ttl=64 rssi=-63 dBm time=13.422 ms (DUP!)
2020-02-20 18:19:38,661 # 12 bytes from fe80::c78:16d9:8aca:ba9a%8: icmp_seq=0 ttl=64 rssi=-44 dBm time=21.819 ms (DUP!)
2020-02-20 18:19:39,648 # 12 bytes from fe80::d0ae:c1b:2054:58e%7: icmp_seq=1 ttl=64 rssi=-44 dBm time=4.797 ms
2020-02-20 18:19:39,657 # 12 bytes from fe80::d0ae:c1b:2054:58c%8: icmp_seq=1 ttl=64 rssi=-61 dBm time=12.917 ms (DUP!)
2020-02-20 18:19:39,666 # 12 bytes from fe80::c78:16d9:8aca:ba9a%8: icmp_seq=1 ttl=64 rssi=-43 dBm time=21.679 ms (DUP!)
2020-02-20 18:19:40,657 # 12 bytes from fe80::d0ae:c1b:2054:58e%7: icmp_seq=2 ttl=64 rssi=-41 dBm time=4.795 ms
```
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