[Please Help] Centos 7 can not ping gateway IP

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Ingenetic
Posts: 3
Joined: 2020/04/06 07:02:42

[Please Help] Centos 7 can not ping gateway IP

Post by Ingenetic » 2022/08/02 01:49:34

hi all,

i have 3 server here, Server A , Server B and Server C , all server IP address on the same subnet , ex :
1. server A = 103.20.12.50( public ip)
2. Server B = 103.20.12.51( public ip)
3. Server C = 103.20.12.53 ( public ip)
Gateway ip = 103.20.12.49 ( public ip)

server A and server B works normally ,
but server C , suddenly last friday get disconnect from internet.
Server C can ping to server A & B , but can not ping to Gateway IP .

First, i thought the NIC is problem, so i put a new one , but the result is the same, server C only can ping to other server on same subnet , but can not ping to gateway IP , so Server C can not connect to the internet , and that server not accessible from the outside (WAN).

As i remember , last year i configure server C ( zimbra mail server ) for firewall :

1. yum install -y firewalld
2. systemctl start firewalld
3. i add this command :

firewall-cmd --permanent --zone=public --add-port=25/tcp
firewall-cmd --permanent --zone=public --add-port=80/tcp
firewall-cmd --permanent --zone=public --add-port=110/tcp
firewall-cmd --permanent --zone=public --add-port=143/tcp
firewall-cmd --permanent --zone=public --add-port=443/tcp
firewall-cmd --permanent --zone=public --add-port=465/tcp
firewall-cmd --permanent --zone=public --add-port=587/tcp
firewall-cmd --permanent --zone=public --add-port=993/tcp
firewall-cmd --permanent --zone=public --add-port=995/tcp
firewall-cmd --permanent --zone=public --add-port=3443/tcp
firewall-cmd --permanent --zone=public --add-port=5222/tcp
firewall-cmd --permanent --zone=public --add-port=5223/tcp
firewall-cmd --permanent --zone=public --add-port=9071/tcp
firewall-cmd --permanent --zone=public --add-port=8443/tcp
firewall-cmd --permanent --zone=public --add-port=7071/tcp
port that zimbra's need to open .

so i try to turn off service firewalld on server C , and yes, it can ping to gateway IP and internet, the server accessible from outside .
but , if i turn off firewalld service, my server being attacked /brute forece on port 7073.

Please help, how to make service of firewalld keep running, but the server can ping gateway ip and can connect to internet .

Best regards,

Whoever
Posts: 1357
Joined: 2013/09/06 03:12:10

Re: [Please Help] Centos 7 can not ping gateway IP

Post by Whoever » 2022/08/03 16:47:32

What's the result of running:

ip route show

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