Why ping not works through Interface name but works through Interface address?

Question

I use a USB-Ethernet Adapter which gets recognized as eth1 in the target. I then set an IP for eth1 using the command

ifconfig eth1 YY.YY.YY.YY

When I use

ping -I eth1 XX.XX.XX.XX

OUTPUT :

mx6q:~# ping -I eth1 192.168.2.35
PING 192.168.2.35 (192.168.2.35): 56 data bytes
^C
--- 192.168.2.35 ping statistics --- 3 packets transmitted, 0 packets received, 100% packet loss

it's not working, whereas when I use

ping -I YY.YY.YY.YY XX.XX.XX.XX

OUTPUT :

mx6q:~# ping -I 192.168.2.99 192.168.2.35
PING 192.168.2.35 (192.168.2.35) from 192.168.2.99: 56 data bytes
64 bytes from 192.168.2.35: seq=0 ttl=64 time=0.765 ms
64 bytes from 192.168.2.35: seq=1 ttl=64 time=0.437 ms
^C
--- 192.168.2.35 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss

it is working.

What should I do to ping through interface name?

IFCONFIG

eth1      Link encap:Ethernet  HWaddr 00:07:40:53:dd:1b  
          inet addr:192.168.2.99  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::207:40ff:fe53:dd1b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
      RX bytes:4754 (4.6 KiB)  TX bytes:1376 (1.3 KiB)

Answer 1

Make sure the interface name is present on your machine. Check by doing ifconfig or ip addr show or ip link show commands.

You can also do some troubleshooting using ip route show and traceroute -i commands.

It is working as shown below:

[iahmad@ijaz-cms ~]$ ping -I enp0s25 www.google.com

PING www.google.com (172.217.18.100) from 137.138.52.207 enp0s25: 56(84) bytes of data.
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=1 ttl=54 time=4.88 ms
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=2 ttl=54 time=4.97 ms
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=3 ttl=54 time=5.01 ms
^C
--- www.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 4.885/4.958/5.019/0.055 ms


[iahmad@ijaz-cms ~]$ ping -I 137.138.52.207 www.google.com

PING www.google.com (172.217.18.100) from 137.138.52.207 : 56(84) bytes of data.
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=1 ttl=54 time=4.98 ms
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=2 ttl=54 time=4.93 ms
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=3 ttl=54 time=4.96 ms
64 bytes from zrh04s05-in-f4.1e100.net (172.217.18.100): icmp_seq=4 ttl=54 time=4.98 ms
^C
--- www.google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 4.939/4.966/4.983/0.017 ms