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

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4
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2answers
102 views

Debugging iptables and common firewall pitfalls?

This is a proposed Canonical Question about understanding and debugging the software firewall on Linux systems. In response to EEAA's answer and @Shog's comment that we need a suitable canonical ...
-1
votes
0answers
15 views

Disable any rule relating to dropping inactive SSH connetion

Can someone walk me through how i could check a firewall for any rules relating to dropping an inactive SSH connection. Have been looking everywhere. Reason i am looking for this is an SSH tunnel ...
0
votes
0answers
19 views

How to properly configure security group at AWS?

I'm trying to reach my server's FTP-port by its Elastic IP. I've configured the security group as follows: Inbound Type Protocol Port Range Destination All traffic All All ...
0
votes
1answer
13 views

Ways of accessing FTP from behind a Firewall without Admin rights? [on hold]

I am regular user sitting behind our office firewall i.e. I do not have admin rights over the system or the network and there is no way I can get either of them. Now I want to copy some content from ...
-2
votes
1answer
50 views

Does AWS EC2 blocks torrent sites like torrentz.eu? [on hold]

Initially when trying ping torrentz.eu, dns was not resolving the torrentz.eu domain name on my AWS EC2 micro instance(Ubuntu), Then I have added google public dns to the resolv.conf. So my instance ...
0
votes
1answer
14 views

sbs 2008 firewall, allowing only 3 IP numbers to connect to port 25, block all others

I need to allow only 3 IP's to communicate inbound with port 25 on my SBS. I set up two rules (one for TCP and one for UDP) where the rule says "Allow the connection" and in Scope under "Remote IP ...
0
votes
1answer
19 views

Setup a very Basic DMZ for WordPress

We are thinking of switching our corporate website from externally hosted and designed, to an internal WordPress server. This is so we can maintain direct control, as well as run our own traffic ...
0
votes
3answers
44 views

iptables actively refused everything despite exceptions

I was following the centos wiki page on iptables but no mater what I change only port 22 opens. Using various port scanning websites they all say the server is actively refusing connections on all ...
0
votes
2answers
112 views

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 ...
1
vote
1answer
15 views

CISCO SSL VPN (multiple Sites) [on hold]

I'm having a small issues and I'm sure it's NAT related. Our Users connect to SSL VPN in Ft. Worth. We also have a site up in Dallas. There is a current Site to Site connection there with full ...
0
votes
1answer
46 views

WAN IP Ranges and NAT [on hold]

Let's say we have a router with a WAN IP assigned by DHCP: 1.1.1.1/255.255.255.255 The ISP subnet for it's lan interface is 82.5.167.161/255.255.255.248 My firewall behind this router is on WAN IP: ...
0
votes
0answers
28 views

Cannot trace bug in iptables firewalls config

I seem to have a bug in my iptables configuration - when I comment out hte final line (drop) it works fine - when I uncomment it, I cannot ssh into my server - can anyone spot what I'm doing wrong? ...
1
vote
0answers
30 views

How to combine multiple route hops using one (pfSense) router?

I am trying to come up with a way to consolidate two routers into one. I have the following network configuration: LAN <-- a/24 --> NAT Firewall <-- x/29 --> Router <-- y/30 --> ...
1
vote
0answers
16 views

Remote WOL over CISCO/FW not Forwarding

I'm trying to accomplish a Wake-on-LAN by triggering the two servers' public IP addresses. Internally, the WOL works like a charm (by either the internal or external IP), externally however, it does ...
-1
votes
1answer
36 views

How to schedule firewall to block wan connection on Windows 7 [closed]

I have a camera on my pc. There are 3 NVR (network recorder ) on different network connected to my cam throug WAN connection. I need to block any NVR from accessing my camera in different hour, and ...
0
votes
1answer
46 views

why my nat iptables rules dont work with marked packets?

System: debian squeeze, Linux server 2.6.32-5-amd64 #1 SMP Tue May 13 16:34:35 UTC 2014 x86_64 GNU/Linux, iptables v1.4.8 lsmod | grep iptable iptable_security 2176 0 iptable_mangle ...
0
votes
1answer
29 views

How to route VPN traffic through a separate internet connection with a SonicWALL firewall?

We have a depot quite some distance from the exchange, the expensive internet connection is only getting 2/1Mb. This causes constant drops as soon as someone downloads anything. We have now got a 4G ...
0
votes
1answer
32 views

rDNS and forward DNS for mail server behind firewall, different IPs

All, Here is my setup : Firewall(x.x.x.114) <--> mail.mailserver.com (FQDN) (x.x.x.118) When sending mail, header has following IP ...."Receivedfrom mail.mailserver.com ([x.x.x.114])", my ...
0
votes
1answer
36 views

Cannot find error in iptables firewall configuration

I'm struggling with a firewall problem on my Centos server. I have the following configuration which when I use it with a service iptables restart and I try to ssh to the server with putty, I cannot ...
0
votes
1answer
15 views

Adding VPN/Firewall to my network

Right my setup is as follows TP-LINK AC1750 Wireless router WAN (Comcast) connects here 1 port connects to TP-LINK 16 port managed switch 16 port switch has static IP, 192.168.0.99 (I've reserved ...
-1
votes
0answers
16 views

Can't connect to SAMBA - ISP is blocking it [migrated]

Security issues aside, I'd like to connect to a SAMBA share from home to a server (dedicated or vps, doesn't matter). The server works perfectly. The issue is on the client side. Let me more clear: ...
-1
votes
1answer
21 views

error 500 web page share point [closed]

In my environment we are having 3 branches eg:A B C all the branches are protected with cyberoam firewall also ..and IP to IP trafiic is Allowed to all three branches. Recently A branch is able to ...
0
votes
1answer
28 views

Configuring iptables for Haproxy

Ubuntu machine running haproxy with 2 network cards, 1 connected to WAN (called wan0) and another connected to LAN (called lan0). All chains set to DROP traffic. # Masquerade traffic from LAN to WAN ...
0
votes
0answers
39 views

ZyWall USG-100 Firewall block access to internal subnet beyond another router

I'm experiencing a strange problem with a ZyWall USG 100 Firewall, that I can't solve with leaving the firewall enabled on the ZyWall. I have the main network subnet that is 192.40.192.0/24(LAN1 on ...
-2
votes
0answers
33 views

Gmail is responding very slow in Google chrome.whereas fast in firefox

gmail works very slow in google Chrome it means when i try to login on gmail it takes too much time to get logged in. whereas it works fine in mozilla firefox. we are using cyberoam as firewall,my pc ...
2
votes
1answer
61 views

Block smtp service to a IP centos 7 Firewall

I would like to know how to block an IP to use smtp service on a server with centos 7 firewall . I try to use something like this : firewall-cmd --permanent --zone="public" --add-rich-rule='rule ...
-2
votes
0answers
23 views

Ports and firewall Rules for Cafe PDQ, CCTV and Customer web browsing

Edit: Question is probably a bit stupid, but now I have written the below, I am getting second thoughts about posting this. But having spent about an 2 hours reading other posts and typing this and ...
0
votes
1answer
44 views

How will the LAN to LAN firewall rule affect the traffic in the rest of the network

I have a following network setup (of course a bit modified from the real situation) I would like to setup a LAN to LAN rule on the ZyWALL firewall so that only certain ports/ip adresses are allowed ...
0
votes
0answers
27 views

rsyslog not discarding despite rule to the contrary

I am running rsyslogd on a new CentOS 6.6 box. I have put in a custom rule to log my firewall messages (via firehol) to a separate file, as per instructions here: ...
0
votes
0answers
35 views

How to block ip/ports using iptables with specific date and time?

Normally to block in command-line I used iptables. iptables -I INTPUT -s xxx.xxx.xxx.xxx -m time --utc --datestart 2013-09-09T15:00 --datestop 2013-09-09T15:30 -j DROP But the problem is, this ...
0
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0answers
25 views

How to forward traffic from ipsec host to local network?

Could anybody explain how to implement forward traffic from host in IPsec to local network. On my server I have 3 network cards: red0 - extern orange0 - dmz green0 - local IPsec builds through ...
1
vote
1answer
41 views

Can't get iptables working in VPS - state and conntrack not possible

I've been browsing and reading documentations all night and I can't figure out any solution... I'm trying to get iptables working on my VPS (Debian 7). But I can't get established connections ...
2
votes
2answers
44 views

Can't SSH, but can TeamViewer [closed]

I would like to SSH into a computer behind a firewall that blocks SSH connections (incoming and outgoing). Amusingly, I can still access the computer using the remote-desktop software TeamViewer. I ...
1
vote
0answers
19 views

UFW Firewall on Ubuntu

I have installed UFW on Ubuntu 14.04. I used following commands to enable a port: sudo ufw allow 9384/tcp When I used the status command (sudo ufw status) it shows me that port is open for both IP4 ...
0
votes
3answers
38 views

Can the firewall prevent the DHCP to give an address, how to fix this?

I am not getting an IP in the subnet 10.0.0.0/24 where the DHCP is working and should serve an IP, I am getting instead only an IP in the subnet 169.254.0.0/16(link local address) that is probably ...
0
votes
0answers
10 views

FreeBSD pf does not allow inbound smtp [duplicate]

I'm trying to figure out why the following simple pf config allows inbound SSH but not smtp (tcp 25). I'm running FreeBSD 10.1-RELEASE-p9, and the SMTP server is postfix 2.11.4. # ...
-1
votes
2answers
53 views

Port forwarding ssh with iptables

Moved from stackoverflow... My new Internet firewall, based on Linux iptables, is working in most regards very well, but the port forwarding does not work: $ ssh -p 7022 [ppp0-ip-address] ssh: ...
0
votes
0answers
63 views

Make NGINX Block All Requests To Direct Server IP - Stop XML-RPC Attacks

Essentially, my website is being attacked by a layer 7 XML-RPC attack and is currently offline and has been offline so I am in need of desperate help. Any assistance would be greatly appreciated :)! ...
0
votes
1answer
43 views

Allowing services to specific hosts using firewalld

Introduction On my database server (CentOS 7) I want to allow access to port 3306 (MySQL) from specific web front-ends (10.10.40.6 and 10.10.40.7 in my example). On top of that I want to allow access ...
1
vote
0answers
23 views

Cisco 5512-x TCP request discarded

We have a fairly basic ACL and NAT rule allowing RDP inbound and NAT'd to a LAN IP (all IPs replaced with IP) object network STATIC-PAT-RDP host IP access-list outside_access_in extended permit ...
0
votes
1answer
110 views

Allow only SSH, FTP and Cloudflare Servers via IPTables

I want to allow only SSH access, FTP access and all communications between my Dedicated Server and all Cloudflare Servers using IPTables. I tried the commands beneath but it seems like I kicked out ...
1
vote
1answer
42 views

FreeBSD pf with NFS

I'm having trouble establishing new NFS connections when my pf is turned on. When I turn off pf on the server and client I'm able to mount with no trouble. I tried keep state and flags S/SA on the ...
1
vote
1answer
54 views

iptables block net range

I'm trying to REJECT network via iptables(8) and for whatever reason it is not doing so: # cat /etc/redhat-release Red Hat Enterprise Linux Server release 6.6 (Santiago) # uname -a Linux X ...
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vote
0answers
10 views

What would cause pysmb to fail when OSX Finder “Connect to Server…” succeeds? [migrated]

(originally asked on StackOverflow, but I think there are more appropriate experts here): I'm trying to transfer a file from a remote samba share (on a windows server) in a python script (running on ...
2
votes
1answer
30 views

Identify individuals behind SLAAC addresses

We're operating an IPv4 network (on ethernet & Wifi) in a student dorm with ~200 users and want to deploy IPv6 in the long term, with stateless autoconfiguration on a single /64 prefix. ...
0
votes
0answers
5 views

firewalld allow connections to a port for only a subnet of IPs [duplicate]

I am on Fedora 21 Workstation on my PC. By default, all ports through firewalld are open on Fedora 21. When I open a service accessible through a port (such as a CouchDB or a SQL server or a simple ...
2
votes
1answer
56 views

How to test iptables settings by port scanning? [closed]

I want to test my iptables and prove that it only allows traffic for given Protocol / Port - combinations. How I can use as a target for a port scan?
2
votes
1answer
74 views

Port 8080 remains closed even when opened with iptable and nodejs is listening on it [duplicate]

I am trying to install a nodejs server listening to port 8080 that I opened with iptable but when I run nmap or a web tools I always get the message that the port is closed. I'm on a Ubuntu vps. ...
1
vote
1answer
108 views

Chinese Firewall DDoS and IPtables not working

Recently my server has been hit with DDoS's coming from the Great Chinese Firewall. As per the advice in one of the replies in mod_security block requests by http-host header, and the advice in ...
0
votes
0answers
53 views

IPTABLES and GEOIP: Show Custom Webpage to Blocked Visitors

Because of legal protection, as a first stage of launching my project I will focus on couple of countries only. The number of supported countries will grow. I know, it is possible to block or allow ...