Firewall Configuration in Linux in Centos 6.2
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netstat -tulpn tells you a lot.
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@thecreativeone91 Ok all.How to design the Firewall block diagram?I need to do basic firewall in Centos and how to do?
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Just as important, or moreso, than a firewall is patching that system. That system is years without patches. It is a VERY dangerous system that you have there.
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@Lakshmana said:
@thecreativeone91 Ok all.How to design the Firewall block diagram?I need to do basic firewall in Centos and how to do?
Never done a block diagram for a firewall. Just need a list of the ports that are needed.
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@scottalanmiller I need to configure basic firewall by opening SSH and Ping ports only.
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Install Fail2Ban as well.
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@thanksajdotcom said:
Install Fail2Ban as well.
Good advice. Fail2Ban is excellent. It automates some important firewall tasks.
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@thanksajdotcom I need to do in IPtables only for the configuration for the firewall at linux OS(Centos)
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@Lakshmana said:
@scottalanmiller I need to configure basic firewall by opening SSH and Ping ports only.
Ping does not use a part. It is not part of either TCP or UDP but of ICMP which is portless.
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@StrongBad How to do a block diagram for designing the Firewall?
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@Lakshmana said:
@StrongBad How to do a block diagram for designing the Firewall?
What do you mean? You need to know which ports to have open, whether that's 80 (HTTP), 22 (SSH), 443 (HTTPS) or what, and then you do a deny all at the bottom, which basically says that if you didn't open it, it's blocked.
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@thanksajdotcom I need to open Port number 22 (SSH),and also Ping.I need to do the block diagram to design the process?
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@Lakshmana said:
@thanksajdotcom I need to open Port number 22 (SSH),and also Ping.I need to do the block diagram to design the process?
As @StrongBad said, ping doesn't have a port. It's ICMP as the traffic type, so it doesn't use a TCP or UDP port. It should be good to go already.
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@thanksajdotcom said:
s ICMP as the traffic typ
OK but how can i make the other system in the same network as well as other network to be easily ping the system. -
ICMP (Ping and TraceRoute) should be enabled by default. Have you tested them to see if they are already blocked?
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@Lakshmana said:
@thanksajdotcom said:
s ICMP as the traffic typ
OK but how can i make the other system in the same network as well as other network to be easily ping the system.If they're on the same network, you don't have to do anything to enable it. Just type ping ip.of.the.device or the hostname.
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@StrongBad said:
ICMP (Ping and TraceRoute) should be enabled by default. Have you tested them to see if they are already blocked?
Exactly. You're freaking out about enabling them when they are enabled by default, so unless you did something SPECIFIC TO DISABLE THEM, they are already working.
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@Lakshmana said:
@thanksajdotcom I need to open Port number 22 (SSH),and also Ping.I need to do the block diagram to design the process?
Port 22 is open by default as well. How did these get closed?
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@thanksajdotcom So now I have to use only SSH as open to use the protocol.How to do block diagram?
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@StrongBad said:
@Lakshmana said:
@thanksajdotcom I need to open Port number 22 (SSH),and also Ping.I need to do the block diagram to design the process?
Port 22 is open by default as well. How did these get closed?
Exactly. Especially if this is a server, you shouldn't have a GUI by default, meaning you MUST have SSH access as it is.
