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

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4
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124 views

Why on linux machines, any packets do not pass except icmp, but correctly pass on windows

There is a cluster on proxmox. In a cluster have vm - configured router (pfsense). In the our net have Windows and Linux machines. There is the problem: Windows-machines have access to the internet, ...
3
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1answer
68 views

Smart solution for XenServer firewall?

I've been searching for a smart solution for a XenServer firewall for about a month now. The documentation for the new default networking backend "openvswitch" is not that detailed and I can barely ...
3
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1answer
852 views

How do I forward/NAT all traffic to one interface/IP to a remote IP?

I have one "server A" that has multiple IPs attached to it, like so: eth0:0 1.1.1.1 eth0:1 1.1.1.2 eth0:2 1.1.1.3 I have another "server B" that also has multiple IPs attached to it, like so: ...
3
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1answer
505 views

cisco asa reloading

After having both memory and code upgrades, we have a significant number of our asa 5520's (in active/standby pairs) develop problems. The problem manifests itself as losing connectivity to the other ...
2
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1answer
24 views

Allow only one ipaddress through a cisco firewall without pcs knowing there is a proxy server

We have a PC behind a firewall. (ASA 5505) [PC] => [ASA Firewall] => [Corporate Proxy/Firewall/Anything] => [Internet] :- where the PC and ASA Firewall are under our control... and the rest are ...
2
votes
1answer
18 views

How to provide access to lan mysql DB from a remote server?

Consider the below network configuration: A client connects with its workstation to the application server on the Web. The application is full HTML, so only browsing through HTTPS is enough to ...
2
votes
1answer
173 views

WiFi landing page: allow facebook + CDNs

we're building a landing page to use with Unifi (v3-beta). The landing page should show a facebook (and later LinkedIn) button to login. After they login with fb (or allow our app) they get ...
2
votes
1answer
77 views

Domain based firewall outbound rules

We have a webserver (IIS) hosting some e-commerce websites. Our firewall in front of the server has a restriction on inbound and outbound traffic. The webserver makes outbound calls to payment ...
2
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1answer
123 views

Cannot directly reject traffic on port 25

My server is running Ubuntu 10.04.4 LTS and I want to reject traffic to port 25. The goal is this: $ telnet {ip} 25 Trying {ip}... telnet: connect to address {ip}: Connection refused telnet: Unable ...
2
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1answer
72 views

postfix stops accepting connections from certain IPs

I had postfix up and running, and I think it was complete, although there was still a little testing to do. But at some point, it stopped accepting connections from my home computer. I tried to telnet ...
2
votes
1answer
244 views

Packets marked INVALID in FORWARD rule

I have a firewall that has 3 IP aliases on 1 physical interface. Packets get dropped between these 3 interfaces (either ICMP, HTTP, or anything else). We tracked it down to these packets being marked ...
2
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1answer
42 views

Assign VPN users to Domain Network

How can I assign VPN users (provided using NPS) to the Domain Network in firewall/network center settings? Currently connection occurs only when I assign a particular rule to the Public network ...
2
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1answer
279 views

IPTables unable to nat trough VPN

I have a VPN connection to a server on a remote location. I want other pc's to be able to reach the webserver on the remote location trough the VPN connector. But i can't get where i want. This is ...
2
votes
1answer
3k views

PPTP connection fails with errors 800/806

I've got a client (Server 2008 R2) that won't connect to our production environment PPTP VPN server (Server 2003, running RRAS). The server is behind a firewall that has TCP1723 open as well as GRE. ...
2
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1answer
262 views

Rackspace Firewall/Gateway Setup

I have rackspace account and wish to have this sort of setup: Firewall/Gateway eth0 - Public IP (56.X.X.X) eth1 - Private IP (10.X.X.X) Ubuntu 10.10. Accepts connections from the internet and ...
2
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1answer
2k views

Watchguard config, drop-in or mixed-routing mode?

I have a Watchguard XTM 2 that is currently acting as a firewall and a router for my business network, I currently have the WG setup in mixed-routing mode and am happy with the current configuration. ...
1
vote
1answer
39 views

Iptables configure gateway virtual machine with 2 interfaces

I have a virtual machine that works like a gateway from other virtual machines. The configuration of the interfaces is the following UBUNTU: eth0: ip: 10.0.2.2 netmask 255.255.255.255 ...
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1answer
37 views

Automatically ask router for port redirection on ubuntu

Is there a way to use uPnp or something to automatically ask a router/firewall to redirect data coming from outside to a machine running ubuntu? Here's the deal, I'm supposed to prepare a certain ...
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1answer
111 views

Is IGMP multicast traffic to a Xen VM host legitimate?

I run two Xen/CentOS 6.5 based VMs, both hosted by the same company, but connected to different networks (basic /24s w/ a single gateway at .1) in different physical locations. I developed an iptables ...
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1answer
85 views

Limit ftp connections with pf firewall at FreeBSD

I want to limit simultaneous FTP connections to my FreeBSD server with the pf firewall. For example that only 10 simultaneous connection are possible to the port 20 or 21 from one source IP. I use ...
1
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1answer
123 views

Should I create a second WAN Interface for a new SSLVPN setup on my Sonicwall 2400?

Sonic Wall 2400 I'm setting up a new SSLVPN on our Sonicwall, very new to this. I currently have an exchange server as well, so mail.company.com is directed to our mail server. I'd like to setup a ...
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1answer
41 views

Outbound ports for a firewall for webserver and db server

I have an environment where there is one firewall, and there is a secure segment and a DMZ segment behind it. There is a bunch of servers in the secure segment - DB server, the QA server, etc and ...
1
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1answer
814 views

Juniper SSG5 DHCP IP Pool is full. Unable to offer IP address to client

hope we have some Juniper guys around, I have configured a Juniper SSG5 as our main firewall/router the DHCP server set on interface bgroup1 to have a rang from 10.10.10.76 to 10.10.10.210 All ...
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1answer
87 views

How to filter TCP packets based on flags using Packet Filter

Well, I didn't know exactly how to ask this question, but I know that you can use the keyword flags to especify which flags you want to filter. According to the documentation of the Packet filter: ...
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1answer
144 views

Configuring a firewall appliance with 2 VLANs - how are the outbound links on the firewall configured?

We just ordered a sonicwall NSA 4500 firewall and I am preparing a network diagram for its arrival. We have 12 servers in a newly setup rack, a 48-port switch, and a Sonicwall NSA 4500 firewall I ...
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1answer
285 views

Dropping incoming requests for a specific file with iptables

Server is a standard LAMP stack configured via cpanel on CentOS 5.9. We have one file, call it bad.php, on one of our domains that is mistakenly being accessed about 10 times a second by a service ...
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1answer
451 views

Per-user dynamic traffic shaping

At work we have a dedicated Internet link for everyday use (servers use a different link) with limited upload bandwidth (currently 3Mbps). Since there are ~80 users, sometimes this upstream link ...
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1answer
394 views

pfsense firewall filter rules behind nat?

i am new in pfsense i have vmware which pfsense and windows xp are installed on them pfsense in using ip 192.168.44.1 for LAN and 192.168.121.129 for wan (which is NAT) my win xp ip is 192.168.44.2 ...
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1answer
154 views

Dual Cisco ASA 5505 passing RSTP in transparent mode

I'm looking at moving to colocation and one area being discussed is networking redundancy. I can get a dual feed from a two different datacentre switches configured with Rapid Spanning Tree Protocol ...
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1answer
140 views

Finding spoofed IP address on network

I have a few IP spoof dropped messages coming out of my Sonicwall firewall, we'll call them Source A and Source B. Both of these sources have the same mac address indicating they're coming from the ...
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1answer
75 views

NAT ports - how do they work?

I have the following network schema: Computer A: three nics: NIC 1 (eth0): dhcp, public internet NIC 2 (eth1): static 192.168.1.1, gateway for Computer B NIC 3 (eth2): static 192.168.2.1, gateway ...
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1answer
310 views

AWS EC2 security group source

I'm currently trying to configure a security group and allow MS SQL connections from my other instance. I want to be able to specify the security group's name as the source. But the connection is not ...
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1answer
687 views

Ubuntu 12.04 open port 80 inside WLAN

I have an nginx server running on ubuntu 12.04 that serves http through port 80 and https through port 443. Everything works fine if I access it from the same computer via localhost, 127.0.0.1 or the ...
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1answer
224 views

Programatically blocking a url to rate limit, unblocking or expiring the block

My requirements are to be able to rate limit or temporarily hard block any requests to our server for a particular URL if the client sends more than x requests per hour. There are about 250K urls ...
1
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1answer
4k views

Handshake violation when trying to access one website

I have a TZ 190 Wireless Enhanced with SonicOS Enhanced 4.2.1.0-20e. Yesterday, people could access without any problems a bank website wich uses HTTPS. Today, it is imposible to access only that ...
1
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1answer
613 views

Amazon EC2 Socket connection not being accepted

I am trying to run a java application on my EC2 instance. The application accepts socket connections on port 54321. If I try and connect to it, it times out. My Security Group is set as: TCP Port ...
1
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1answer
272 views

APF - allow_hosts.rules - Port Ranges [error]

I am running into a problem trying to specify that webmin can only be accessed from my private IP. But I can get the port ranges to correctly work. I am using this in the allow_hosts.rules file. ...
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1answer
317 views

How to secure a Windows SBS Server against fraudulant login attempts?

I administer a Windows Small Business Server 2003 R2 server for a small business. The only ports that this server has exposed to the internet are SSL and the RDP tunnelling port used by the SBS remote ...
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1answer
124 views

Firewall management in Windows Web Server 2008

I've been trying for hours to block a single port(sql server) from remote access. In linux a single line of iptables command would be enough. In 2008 i couldn't manage to make it happen. The ...
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1answer
1k views

Why won't vyatta allow SMTP through my firewall?

I am setting up a vyatta router on VMware ESXi, But I see to have hit a major snag, I could not get my firewall and NAT to work correctly. I am not sure what was wrong with NAT but it "seems" to be ...
1
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1answer
1k views

ClearOS transparent firewall and web proxy mode possible?

In other firewall software packages I have seen the ability and am hoping it is possible with ClearOS to put it in to transparent or bridged mode where the device sits physically between the client ...
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1answer
281 views

How can Rackspace cloud servers be set up with an EC2 type approach to firewalls?

I'm looking at using Rackspace cloud servers for some Windows based web hosting, and having used Amazon EC2 for similar projects before, I was disappointed to find Rackspace don't employ the EC2 ...
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1answer
570 views

csf dovecot and IP blocking

I'm using csf and noticed a lot of brute force password attempts into a particular pop3 account. csf does not appear to be blocking the IP addresses as it does with other processes. Is there a switch ...
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1answer
253 views

iptables packetfilter on virtual bridge

I'd like to filter packets passing through a virtual bridge on a Fedora Linux machine. I've enabled the following sysctl options as described in multiple guides: net.bridge.bridge-nf-call-ip6tables = ...
1
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1answer
402 views

How to detect pid that generates outbound traffic on Solaris?

Is there a firewall of some sort on Solaris that will let me define a filter, for instance outbound traffic to a certain range of ip adresses and port, but instead of blocking the traffic I want to ...
1
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1answer
182 views

Random ports open on VPS box

I have a VPS box I just purchased. It is running Apache and SSHD on their default ports. When I do a port scan, I get results back that say port 139 and various other seemingly random ports are ...
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1answer
231 views

ESX Firewall Command Troubles

I am working on creating some firewall rules to stop some of the SSH brute-force attacks that we have seen recently on our ESX server hosts. I have tried the following rules from the CLI to first ...
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1answer
416 views

Can ping, can establish SSH connection in one way but not on other way

First of all, sorry about my english. We're facing a very strange problem with SSH connection between two specific servers. Let's say we have X1, X2 and Y servers. Where X1 and X2 are behind the ...
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1answer
185 views

Help me better automate changes to our static routes

I have been assigned the task of maintaining and configuring my organization's firewall and gateway routers, and I'm looking for some advice on how to manage the static route table. (As context, ...
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1answer
154 views

windows 7 firewall logging PID

i enabled my windows 7 firewall to by default block all outbound connections by default. i configure each and every program that needs network access in the 'Windows Firewall with Advanced Security' ...