Network troubleshooting - mikec964/chelmbigstock GitHub Wiki

Find out your IP address:

Robin:hadoop-2.6.0 mikec$ ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
	options=3<RXCSUM,TXCSUM>
	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
	inet 127.0.0.1 netmask 0xff000000 
	inet6 ::1 prefixlen 128 
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>
	ether 00:22:41:1e:fe:7d 
	inet6 fe80::222:41ff:fe1e:fe7d%en0 prefixlen 64 scopeid 0x4 
	inet6 2601:6:5e00:17c:222:41ff:fe1e:fe7d prefixlen 64 autoconf 
	inet6 2601:6:5e00:17c:d8ae:6f8c:fb12:3cc3 prefixlen 64 autoconf temporary 
	inet 10.0.0.17 netmask 0xffffff00 broadcast 10.0.0.255
	media: autoselect (100baseTX <full-duplex,flow-control>)
	status: active
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	ether 00:21:e9:d9:79:b4 
	inet 10.0.0.18 netmask 0xffffff00 broadcast 10.0.0.255
	media: autoselect
	status: active
fw0: flags=8822<BROADCAST,SMART,SIMPLEX,MULTICAST> mtu 2030
	lladdr 00:21:e9:ff:fe:ca:ff:10 
	media: autoselect <full-duplex>
	status: inactive
en2: flags=8822<BROADCAST,SMART,SIMPLEX,MULTICAST> mtu 1500
	ether 0b:0b:0b:0b:0b:0b 

Ping:

$ ping <ipaddr|hostname>
$ ping -c 5 robin # ping 5 times
Robin:hadoop-2.6.0 mikec$ ping -c 3 10.0.0.1
PING 10.0.0.1 (10.0.0.1): 56 data bytes
64 bytes from 10.0.0.1: icmp_seq=0 ttl=64 time=0.960 ms
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=1.152 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=1.031 ms

--- 10.0.0.1 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.960/1.048/1.152/0.079 ms

Show your hostname:

$ hostname

Show list of hosts:

$ cat /etc/hosts

Find hosts on network. Ping 10 seconds, then check addresses. If you know the mac address of your Pi, then you might be able to find it online with this.

$ ping -t 10 192.168.1.255
$ arp -a

Find all devices on the LAN (Linux, not Mac):

nmap -sP 192.168.2.*

See routing table:

Robin:hadoop-2.6.0 mikec$ netstat -nr -f inet 
Routing tables

Internet:
Destination        Gateway            Flags        Refs      Use   Netif Expire
default            10.0.0.1           UGSc            7       48     en0
default            10.0.0.1           UGScI           0        0     en1
10/24              link#4             UCS             5        0     en0
10/24              link#5             UCSI            1        0     en1
10.0.0.1           e8:3e:fc:85:f8:41  UHLWIi          7        0     en0    692
10.0.0.17          127.0.0.1          UHS             2        1     lo0
10.0.0.18          127.0.0.1          UHS             0        6     lo0
10.0.0.26          0:16:cb:b0:4e:6    UHLWIi          0      190     en0   1066
10.0.0.36          20:c:c8:35:ad:28   UHLWIi          0      228     en0   1189
10.0.0.36          c:84:dc:7b:ff:2f   UHLWIi          0        0     en1   1189
10.0.0.255         ff:ff:ff:ff:ff:ff  UHLWbI          0       51     en0
127                127.0.0.1          UCS             0        0     lo0
127.0.0.1          127.0.0.1          UH              1    49369     lo0
169.254            link#4             UCS             0        0     en0