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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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Sizing Firewall for Micro-Datacenter

We have a small data center we're finishing. We have a core+spline and then redundant TOR switches. Everything is basically whitebox 10gb switches running Cumulus; although, we will upgrade the core within the next 12 months to be 40gb, but this…
Ethode
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ASA INSIDE to INSIDE traffic being dropped

An ASA 5505 is being used to route between two networks as it contains routes to everything. The following depicts the network topology. I have tried various combinations of access lists such as: access-list INSIDE_TO_INSIDE extended permit ip any…
WCCPGuy9898
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Azure ARM VM creation with Network Security Groups

I have a network with enabled Network Security Groups where I deny Outbound Port 80 and 443. All Outbound traffic is managed through a Squid Proxy. Now, I want to create a new Virtual Machine in this Network using the Azure ARM templates using the…
Andy K
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UFW: How to block http requests on another port than 80?

I am running an application on port 7000 which is part of a network. So it has to communicate over port 7000 with all other servers of the network (not LAN, dynamic IPs). It has also a web frontend you can access at http://my.ser.ver.ip:7000 but I…
John Doof
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Failed to open a port in my ubuntu machine

Recently I added to iptables a rule which was supposed to allow incoming traffic through port 993. The rule I used is the one shown below: sudo iptables -A INPUT -p tcp --dport 993 -j ACCEPT After I entered the rule, I ran "iptables-save >…
Wonderhost
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Cannot download some files from a given server

I'm working on a Fedora Core release 6, and whenever I want to download a given file from a FTP site, the connection is refused: $ curl --ftp-pasv "ftp://ftp.ensembl.org/pub/current_mysql/vega_mart_56/CHECKSUMS.gz" curl: (7) couldn't connect…
Pierre
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Why is TTL increasing? (and generally behaving erratically)

Summary: TTL is not decremented when pinging hosts on a "network path" My laptop (10.10.13.10) is connected via OpenVPN to a server (10.10.13.1) which hosts several network interfaces. One of them is 10.10.10.254, the gateway to the 10.10.10.0/24…
WoJ
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Do firewalls drop udp dns queries that are longer than 512 bytes?

bottom line: DNS' RFC notes that DNS queries over UDP are limited to 512 bytes. Does anybody know if this is enforced by major corporate firewalls? long story: My company develops a product that should communicate between data centers. Since the…
nadiv
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Granular Windows firewall rule control

Is there a way using group policy (or some other built in mechanism) to apply firewall rules in such a way that a subset of the rules are locked and cannot be changed or overridden, but another subset can? For example I want to lock down the Core…
Nov2009
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Modifying libvirt firewall rules between virtual networks

On my my VM host, I have two libvirt virtual networks: virbr0: 192.168.122.1/255.255.255.0 virbr1: 192.168.130.1/255.255.255.0 I have a VM behind each of those virtual networks. Machines can see the host, and see the Internet. However, when I try…
Joshua Kugler
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Cisco ASA 5505 - Help understand/update the config

Let me preface by saying I am not a network administrator by trade and this firewall was set up originally by a Cisco consultant who is no longer available. We have a small office with a Cisco ASA 5505, and have an IP based printer. This printer is…
david
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Limit number of incoming packets per second for a INPUT UDP port [per IP only, not globally] [Ubuntu IPTables]

I searched and I can't find a rule to limit the count of the incoming packets for a INPUT UDP port per second and per IP. I need that per all IPs that connect to my socket, not for a specific one. I'm using iptables on Ubuntu 14.0.4 LTS amd64. I am…
rez
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How to setup a whitelist using iptables and ipset

I'm trying to only accept connections from my whitelist on ports 53, 80 and 443. Here is my iptables file # Generated by iptables-save v1.4.21 on Thu Feb 25 18:28:29 2016 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A…
chovy
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Correct OpenWRT configuration for iptables PREROUTING rule

I've recently switch my router firmware from Tomato to OpenWRT. I had the iptable commands below which would intercept http requests to an internal ip (192.168.1.254) on port 80 and redirect to a different internal ip (192.168.1.133) on port 8082.…
Shawn McGough
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CentOS Firewall Contingency

What happens if the firewalld service fails to start on CentOS 7? Will the network still function? Will firewall rules still be partially enforced? If the firewall rules are not enforced, is there a way to shut off network services automatically?
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