I can ping other node:
```
/ # ping ipfs1
PING ipfs1 (172.18.0.2): 56 data bytes
64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.111 ms
64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.084 ms
64 bytes from 172.18.0.2: seq=2 ttl=64 time=0.083 ms
^C
--- ipfs1 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 0.083/0.092/0.111 ms
```