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

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Point fail2ban to new log, without losing current bans?

I have logs in /var/log/syslog/YYYY-MM-DD/file.log files. New directories are created automatically by rsyslog, and logs are automatically put to new locations. Every day, I archive previous day of ...
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1answer
198 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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27 views

VPN Full Functioning Then Enabled 2nd NIC now VPN not functioning

I had a successful VPN solution stood up on a Dell PE 2650. I configured Ethernet Bridging and all was well. Following the successful configuration and connection of a few clients, I got greedy. I ...
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2answers
322 views

Opened some ports with iptables but they aren't open

I'm running a Debian 7 server via Linode VPS, and have recently installed/configured a mail server using Postfix and Dovecot. The final step to complete this was to open up ports 993, 995, 465, and ...
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2answers
133 views

Win7 ignores Firewall for RemoteDesktop via GPO

Windows 7 ignores the firewall rule from Group Policy, that should restrict RemoteDesktop to certain IP addresses. It works for XP, but Win7 machines still allow Remote Desktop from everywhere. I ...
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1answer
46 views

Unable to connect to SQL Server over Azure Point-to-site VPN

I'm having trouble connecting to SQL servers over an Azure point-to-site VPN. SQL Standard is running on an Azure VM which is part of an Azure point-to-site VPN. It is a named instance. SQL Express ...
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2answers
629 views

iptables configuration for docker containers

I am using Docker 0.7.0 to create containers on RedHat Enterprise Linux 6.5. When firewall is turned off containers can talk to outside world, but when firewall is on, container cannot be accessed ...
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1answer
112 views

Tools for detecting network traffic filtering [closed]

In Iran we have an ongoing problem with the govt. blocking and manipulating various network protocols. I'm looking for a tool, framework or platform to help us analyze and report on any of these ...
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58 views

My SonicWALL PRO 3060 doesn't have PortShield, but is there a way I can fake it?

So I'm setting up a SonicWALL PRO 3060 and I noticed that it doesn't have some optional PortShield upgrade -- oh well, my loss. However I find that I've started needing something very ...
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2answers
325 views

Avahi (zeroconf/bonjour) service in bridged VirtualBox sometimes not found outside host

I have a VirtualBox with Debian 3.2.51 guest (vcube) on Ubuntu 13.10 host (ring) with a bridged network adapter. vcube has an Avahi service configured with a vcube.local name. I can see/ping/access ...
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3answers
756 views

iptables error: unknown option --dport

The command iptables no longer recognizes one of the most commonly used options when defining rules: --dport. I get this error: [root@dragonweyr /home/calyodelphi]# iptables -A INPUT --dport 7777 -j ...
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1answer
259 views

Can't establish connection on port 80 for yum

Hi guys I have a very strange issue happening on one of my boxes. If someone can advise what I can check please let me know. Thanks. Here's the layout. Box 1 & Box 2 <> Firewall <> ...
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155 views

Vyatta Remote Access VPN firewall (PPTP)

I am using Vyatta Remote Access VPN (PPTP) and NAT for proxy. When pc-A and pc-B are connected to VPN, pc-A ipaddress is 192.168.10.10 and pc-B is 192.168.10.11. ...
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1answer
81 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 ...
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1answer
102 views

iptables alternative for nat in windows

When setting up a comms server I usually use iptables in linux to forward any incoming connections on a particular port to another server, e.g. Chain PREROUTING (policy ACCEPT) target prot opt ...
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1answer
65 views

Allow access to certain ports on the server, via only one of the server IP addresses

I'm trying to allow access to certain ports on the server, via only one of the server IP addresses. So for example if the server has two IP addresses: 1.1.1.1 1.1.1.2 I only want for example ports ...
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2answers
81 views

How to spoof an IP for application that needs this particular IP?

In general, such a problem, there is a system RHEL 6.4 Server with a pair of network interfaces combined into one by bonding. This system IP address: 10.7.7.1. Next on the system running an ...
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1answer
44 views

A way to only allow some ports on windows server

I have been trying to make this work the last few hours but haven't come far. I have a windows server 2008 and a set up Local Security Policy firewall yet "no" inbound rules (yet). My domains look ...
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2answers
101 views

iptables - allow connections to a port only for IP addresses with established state on a different port

I want to allow connections on port x for IP addresses that have a 'established' state on port y. Is this doable by just using iptables?
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1answer
120 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 ...
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136 views

Dropping packets with Open Vswitch and OpenFlowControl

I am trying to setup some Flows with ovs-ofctl to block all unwanted incoming packets for a VM. The commands I use are: ovs-ofctl add-flow xenbr0 "priority=65000, table=0, tcp, dl_src=*, nw_src=*, ...
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2answers
78 views

IPtables NAT puzzler: Why is traffic from the firewall host being NATed even though it's not coming from one of the prescribed source addresses?

I run a small network where a linux web/mail server also provides NAT for a collection of windows boxes. One of these windows machines is apparently misbehaving (ZeroAccess botnet even though I can't ...
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1answer
111 views

Firewall rules using iptables using conditional statement

I have firewall rule that should accept all the connections, but drop connections from a ssh brute force attack (except 10.0.0.0/8 range). This rule will block an IP if it attempts more than 24 ...
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1answer
126 views

iptables DROP all access except my dynamic IP, is it possible and how/workaround?

If not possible, is there any workaround without affecting CPU performance? iptables -A INPUT -p tcp --dport 80 -j DROP
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1answer
71 views

Server sending packets every 5 minutes to 3 IPs

Been noticing in our firewall logs that three connections are being constantly established every 5 minutes from our web server and trying to send a packet to destination port 43 (whois port) cycling ...
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1answer
80 views

Can browse ftp.microsoft.com but not our own FTP site in IE

We want to have an FTP site that works the same way ftp://ftp.microsoft.com works. We want to be able to browse the FTP site in web browsers. It seems that just recently, users are unable to ...
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1answer
437 views

Install watchdog and firewall on Plesk 11.5

As far as I know Plesk arrives with Firewall and Watchdog out of the box, but now I'm working on a new server with Plesk 11.5.30 and I the Extensions Management page is empty. How can I install the ...
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1answer
37 views

Access to Google's blacklists for my firewall

I know that certain google products automatically access Google's blacklist database. Can I do the same? Is there maybe a cleaned-up dns server against which I could verify my own dns queries? Or some ...
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2answers
231 views

Iptables blocking smtp

Iptables is blocking outgoing and incomming smtp on my server, although I specified it not to. My policies are DROP everything except what's specified. Changing policies to ACCEPT everything "solves" ...
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1answer
67 views

How to block/ban clients that try to access some paths / urls?

Some spambots hammer my server with nonexisting paths like /user/pass?=asdfdasfas How could I block any access to /user/pass?=* ? Is there a better tool than iptables or csf for catching such crap?
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125 views

Blocking X-forwarded-For IP in fail2ban?

I am using a reverse proxy in front of my web-server. In the web server I installed fail2ban and want to use it to monitor logs and block bad ip. I am using nginx with the http realip module. But ...
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1answer
46 views

How to proxy to a web server on a node that can make outgoing connections but has no accessible IP, without root?

Not sure if this is the right StackExchange site to ask (I mainly frequent SO), but since you guys are server admin experts hopefully you'll find it relevant! Some context: I'm currently trying to ...
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36 views

Manual firewall configuration with SuSEfirewall2

I have a Suse server and I want to configure its firewall settings by manually editing the SuSEfirewall2 file (located in /etc/sysconfig/SuSEfirewall2). My goal is to accept only specific services on ...
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1answer
154 views

Does Fortigate 100A support IPv6? [closed]

Tried searching through the net but couldn't find any info since the product is already discontinued. Can anyone confirm if this particular product supports IPv6?
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1answer
163 views

Will using iptables DROP target result in socket CLOSE_WAIT that never completes?

I have some simple rules to block certain IP blocks used frequently by hackers/spammers, e.g.: iptables -A INPUT -s 173.208.250.0/24 -j DROP But, I noticed that apache hangs after a couple of days ...
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1k views

CentOS 6 and PostgreSQL - Can't Connect to Port

SOLUTION: it turns out the ORDER of iptables matters. The firth INPUT rule is REJECT all ... which precludes the ACCEPT rule. So I had to use iptables -I INPUT 5 ... to add the rule in the fifth ...
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39 views

Ideas for redundant / geographically optimized web hosting solution

I need to setup a web hosting solution with the following requirements: No single point of failure. Ability to handle reasonable DDOS attacks (non traffic saturation types) Servers located in ...
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2answers
438 views

MySQL / Firewall / Can't connect to MySQL server

I have a client running a mysql server with bind-address=0.0.0.0. Here is the iptables output root@host:/var/www# iptables -L Chain INPUT (policy ACCEPT) target prot opt source ...
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1answer
139 views

Outbound HTTP traffic being blocked by APF - outbound filter is off

I'm using CentOS 6.4 inside an OpenVZ container. I'm trying to configure APF 9.7-2 to allow inbound SSH and HTTP traffic (only) and outbound HTTP and HTTPS traffic (don't care much if other outbound ...
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1answer
69 views

Limit HTTP method on ubuntu 12.04 server

For starters, this is not a web server. I would like to allow or deny HTTP methods on various ports on the server itself. Ideally could write rules like UFW only extended to include the HTTP method ...
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216 views

Sonicwall NSA 2400 Not switching back to Primary VPN after Failover

We are experiencing an issue with our SonicWall NSA 2400 Firewall. We have a secondary gateway over IPSec setup in the event of a failure of our main ISP (which is unfortunately common). The ...
0
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1answer
106 views

Application Unable connect Remote Server. FIREWALL Issue

Developing a C# Application that uses an WDSL/SOAP service and connects to a server via port 443 I know it is a Firewall Windows 2008 Server issue. Because when I disable it, it works perfectly. ...
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2answers
37 views

Active directory and firewalls

I am not familiar with active directory and have very limited knowledge of firewalls. I am trying to understand how 'trusts' work. Say there is a situation like the following: There are 2 ...
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1answer
257 views

why does yum update fail in cent os 6.4 when wget and curl succeeds

I am using Cent OS 6.4 in a corporate lab and the yum update fails with the below error: I am able to access the same repositories through browser. [root@LAB1 ~]# yum update Loaded plugins: ...
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1answer
309 views

OpenVPN and port 1194 closed

I installed openVPN on my server. By default, the port 1194 is choosed. The problem is that when I am running: sudo nmap -sU localhost -p 1194 It shows me: PORT STATE SERVICE 1194/udp ...
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214 views

Cisco ASA/PIX Can't Access Internal Resources Behind NAT [duplicate]

My servers are natted 1:1 as follows, i.i.i.i maps to x.x.x.x where i is an internal IP, and x is the external IP. From an i.i.i.i machine, I cannot access x.x.x.x resources... What special ...
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1answer
189 views

Cannot connect to remote port 465

I (actually, not me, rather a friend of mine) have a very strange issue. There's a VPS with CentOS, probably version 5: Linux [hostname] 2.6.18-274.7.1.el5xen #1 SMP Thu Oct 20 17:43:28 EDT 2011 i686 ...
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30 views

Zyxell USG200 NAT for local computer using wan address

My WAN public address is linked to the server with NAT. How can I set up the firewall to let all local computer use the same NAT rules for www.mypublicaddress.com address from INSIDE the network? I ...
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1answer
56 views

Best practice to create large hardware VPN

I do have a task to connect 200 small offices to one central using hardware VPN. The server side is Dell Sonicwall NSA 3500 and the client side is DLink DSR 250n. As I dont have much experience on ...
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535 views

Mikrotik router RDP brute force blocking with whitelist

Masters, We have a miktorik router, and we would like to block RDP brute force, but we need whitelist also to allow our collegaues to connect without blocking them. (they sometimes hitting wrong ...