The servo was down and were not able to ping.
Reset the servo and DUT, Router and able to ping them all now.
Please rerun the test and update the results.

jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1
PING chromeos2-row11-rack4-host1.cros.corp.google.com (100.115.244.19) 56(84) bytes of data.
64 bytes from 100.115.244.19: icmp_seq=1 ttl=59 time=1.10 ms
64 bytes from 100.115.244.19: icmp_seq=2 ttl=59 time=1.20 ms
64 bytes from 100.115.244.19: icmp_seq=3 ttl=59 time=1.20 ms
^C
--- chromeos2-row11-rack4-host1.cros.corp.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 1.108/1.169/1.201/0.058 ms
jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1-router
PING chromeos2-row11-rack4-host1-router.cros.corp.google.com (100.115.244.69) 56(84) bytes of data.
64 bytes from 100.115.244.69: icmp_seq=1 ttl=59 time=1.00 ms
64 bytes from 100.115.244.69: icmp_seq=2 ttl=59 time=0.959 ms
64 bytes from 100.115.244.69: icmp_seq=3 ttl=59 time=0.866 ms
64 bytes from 100.115.244.69: icmp_seq=4 ttl=59 time=0.976 ms
64 bytes from 100.115.244.69: icmp_seq=5 ttl=59 time=1.01 ms
64 bytes from 100.115.244.69: icmp_seq=6 ttl=59 time=0.925 ms
^C
--- chromeos2-row11-rack4-host1-router.cros.corp.google.com ping statistics ---
6 packets transmitted, 6 received, 0% packet loss, time 5004ms
rtt min/avg/max/mdev = 0.866/0.956/1.013/0.061 ms
jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1-servo
PING chromeos2-row11-rack4-host1-servo.cros.corp.google.com (100.115.244.119) 56(84) bytes of data.
64 bytes from 100.115.244.119: icmp_seq=1 ttl=59 time=0.746 ms
64 bytes from 100.115.244.119: icmp_seq=2 ttl=59 time=0.743 ms
64 bytes from 100.115.244.119: icmp_seq=3 ttl=59 time=0.730 ms
64 bytes from 100.115.244.119: icmp_seq=4 ttl=59 time=0.744 ms

From my understanding, this is hostapd issue and not connectivity. I just checked the stumpy router associated with the DUT has a very old build. I will update to the latest one, I see in the update router script and will check, if the issue goes away. If it persists, we can try adding a new whirlwind router.

We will need to change the  stumpy router with a whirlwind @chromeos2-row11-rack4-host1-router. This is a conductive setup. 

chromeos2-row11-rack4-host1 stumpy conductive was replaced with whirlwind conductive test bed. 


jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1
PING chromeos2-row11-rack4-host1.cros.corp.google.com (100.115.244.19) 56(84) bytes of data.
64 bytes from 100.115.244.19: icmp_seq=1 ttl=59 time=1.24 ms
64 bytes from 100.115.244.19: icmp_seq=2 ttl=59 time=1.18 ms
64 bytes from 100.115.244.19: icmp_seq=3 ttl=59 time=1.20 ms
^C
--- chromeos2-row11-rack4-host1.cros.corp.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2011ms
rtt min/avg/max/mdev = 1.186/1.213/1.249/0.048 ms
jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1-servo
PING chromeos2-row11-rack4-host1-servo.cros.corp.google.com (100.115.244.119) 56(84) bytes of data.
64 bytes from 100.115.244.119: icmp_seq=1 ttl=59 time=0.801 ms
64 bytes from 100.115.244.119: icmp_seq=2 ttl=59 time=0.772 ms
64 bytes from 100.115.244.119: icmp_seq=3 ttl=59 time=0.721 ms
^C
--- chromeos2-row11-rack4-host1-servo.cros.corp.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 0.721/0.764/0.801/0.045 ms
jongkyuj@jongkyuj0:~$ ping chromeos2-row11-rack4-host1-router
PING chromeos2-row11-rack4-host1-router.cros.corp.google.com (100.115.244.69) 56(84) bytes of data.
64 bytes from 100.115.244.69: icmp_seq=1 ttl=59 time=1.02 ms
64 bytes from 100.115.244.69: icmp_seq=2 ttl=59 time=1.00 ms
64 bytes from 100.115.244.69: icmp_seq=3 ttl=59 time=0.804 ms
^C

Ran few test cases and no longer see "Timed out" error.