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Questions tagged [firewall]

A Firewall is an application or hardware device used to inspect and filter network traffic.

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Exposing multiple servers behind NAT using a single public IP address

This is a Canonical Question about NAT and DNS I'm currently trying to set up a network with a DMZ containing a web server and an e-mail server separated from the Internet by a network address translating (NAT) firewall. I have installed the NAT…
Atrotygma
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Open Windows Firewall to all connections from specific IP Address

Is it possible to "whitelist" an IP Address in the Windows Firewall and allow all connections from that specific address?
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Disable Windows Server Network Locations

I'm not sure what exactly this feature is called. But in Windows Server 2008, it has the Vista Public/Private/Domain locations. This makes sense for laptops, and none at all for servers. My problem is that sometimes some network adapters decide…
MichaelGG
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In the output of `last`, what does suffix ".d" after an IP address mean?

In order to find out who was logged in recently on my server I am using the command: There were logins from very strange IP addresses e.g.: username@pc:/home/user$ last username pts/16 59.224.XX.178.d Sun Aug 2 12:26 - 12:27 (00:00) (where…
Jimmy88
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iptables management tools for large scale environment

The environment I'm operating in is a large-scale web hosting operation (several hundred servers under management, almost-all-public addressing, etc -- so anything that talks about managing ADSL links is unlikely to work well), and we're looking for…
womble
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Making iptables easier to maintain

My network is completely locked down except for a few sites which are whitelisted. This is all done through iptables, which looks something like this: # Allow traffic to google.com iptables -A zone_lan_forward -p tcp -d 1.2.3.0/24 -j ACCEPT iptables…
Big McLargeHuge
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Hardware firewall vs VMware firewall appliance

We have a debate in our office going on whether it's necessary to get a hardware firewall or set up a virtual one on our VMWare cluster. Our environment consists of 3 server nodes (16 cores w/ 64 GB RAM each) over 2x 1 GB switches w/ an iSCSI shared…
Luke
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A secure, standard iptables rule-set for a basic HTTP(s) webserver

I have been trying to put together a basic server iptables script that will work for most sites just running a basic webserver using HTTP(S) and SSH (ports 80, 443, & 22). After all, most VPS only need these starting ports rules and can add mail or…
Xeoncross
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What is an edge server / router / device?

What is an edge server? We see some references to them, but we never see a definition.
Some Student
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How big of a problem is it to punch a hole in the DMZ to one web server?

We currently have our web server in a DMZ. The web server cannot see anything within the internal network, but the internal network can see the web server. How safe would it be to punch a hole in the firewall between the DMZ and the internal network…
Mike Wills
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Stop China from connecting to my Google Compute Engine server

My company has a Google Compute Engine server hosted in North America. We get so many Chinese IP addresses sending requests to port 11 that it is costing us money for the ingress. Our firewall blocks all connections to China already as they have no…
josh123a123
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linux: traceroute send operation not permitted for remote server

When I try to traceroute to a remote ip, I get send: Operation not permitted When I stop iptables, traceroute works fine. So, I assume I need some ip rule for send. What would that rule be? I did find a solution here…
giorgio79
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What is the right iptables rule to allow apt-get to download programs?

When I type something like sudo apt-get install firefox, everything work until it asks me: After this operation, 77 MB of additional disk space will be used. Do you want to continue [Y/n]? Y Then error messages are displayed: Failed to fetch:…
anthony01
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Is my TCP connections sabotaged by my country's government?

I am suspicious that my country's government is destroying the received ACK packet on TCP connections, somehow. When I try to establish a TCP connection to an outside host on ports other than 80 the TCP handshake will not be successful. I captured…
Mohammad
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What should I consider to secure SVN on Windows?

Currently I am using VisualSVN Server and it's only accessible on my home network. Eventually there will be others accessing it, but for now it's just me and I would like to be able to go down to the coffee shop (or wherever) and be able to work…
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