Member Avatar for aman_dba

HI friends,

I have checked the forums, until i loose my patience, but didnt get any such query or reply, so finally posting my issue.
I hav a CentOS box installed as a server with static ip and windows client using it to connect to internet via squid(the proxy server) on LAN
Now wen i try to connect my Linux box outside my LAN, it is not even giving any reply to ping.
Do i need any specific settings with respect to static ip, to make it accessible outside the LAN.
Mentinable:- i hav installed squid for proxy server and samba for File accessing on LAN.

any kinda support will be appreciated
thanks

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Dani AI

Generated

— ping not replying from outside almost always points to one of three things: the server is on a private LAN address and the router/ISP is doing NAT, a firewall (on the router or the CentOS box) is blocking ICMP/ports, or the ISP is filtering incoming traffic. Squid and Samba on the LAN do not, by themselves, make the machine reachable from the Internet.

Useful checklist and quick diagnostics (run from the CentOS box and from a LAN host):

# on the server
ip addr show
ip route show
iptables -L -n

# on any LAN host (to discover public IP)
curl ifconfig.me

# from an external host (to test ports)
nmap -Pn -p22,3128 <public-ip>
telnet <public-ip> 22

Key points to interpret results:

  • If the server IP is in 10.0.0.0/8, 172.16.0.0/12 or 192.168.0.0/16, it is private. A private IP is not directly reachable from the Internet unless the router has port forwarding or the ISP provides a public IP (no double-NAT/CGNAT).
  • If the router responds to ping but the server does not, enable/inspect NAT/port-forwarding on the router (forward TCP 22 for SSH, 3128 for Squid if remote proxy use is intended). If the router does not respond, the ISP or router firewall may be blocking ICMP.
  • Check/temporarily disable the server firewall to test reachability. CentOS examples:
    
# CentOS 6 and older
service iptables stop

CentOS 7+

systemctl stop firewalld

or (to open SSH)

firewall-cmd --permanent --add-service=ssh
firewall-cmd --reload



Security cautions: do not expose Samba ports (137/139/445) to the Internet. Opening Squid as a WAN-facing proxy without access controls invites abuse. If the public IP is behind CGNAT, request a public IPv4 from the ISP or use an outbound reverse tunnel (SSH/ngrok) as a workaround.
Member Avatar for aman_dba

do let me know if u face same issue

thanks anyways...

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