Update: It turns out, our in-house network suppresses pings. I demonstrated this by turning my phone into a hot-spot (thus changing my outbound gateway), connecting with a laptop, then pinging the servers, which worked as expected. ::pulls hair out::
I've inherited two Ubuntu servers that seem to be configured to reject PING requests. My goal is to re-enable pinging for diagnostic purposes.
Things I've tried to enable pinging:
Based on instructions from here, I executed this command:
echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all
Then added the following instruction to
/etc/sysctl.conf so it's enabled on boo. This instruction was not already present:
ufw, I followed the steps noted in this SO thread: In the file
/etc/ufw/sysctl.conf, I found this rule. I did not have to add it.
I also added rules to
-A ufw-before-input -p icmp --icmp-type echo-request -m state --state ESTABLISHED -j ACCEPT
-A ufw6-before-input -p icmpv6 --icmpv6-type echo-request -m state --state ESTABLISHED -j ACCEPT
Then restarted that service.
service ufw restart
I added some
iptables entries I found by Googling. (I'm showing only the relevant rules in the list.)
root@tatooine:~# iptables --list ACCEPT icmp -- anywhere maskedpath.linode.com icmp echo-request state NEW,RELATED,ESTABLISHED ACCEPT icmp -- anywhere anywhere state NEW icmp echo-request Chain FORWARD (policy DROP) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination ACCEPT icmp -- maskedpath.linode.com anywhere icmp echo-reply state RELATED,ESTABLISHED
So my question is: In order to enable pinging, are there additional configurations I am not checking? Alternately, could the
ufw rules be loading from a different file? (And if so how can I find that file?)
Thanks in advance for any help!