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

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cisco asa public server nat issue

I have been tasked with some ASA configuration coming in a few weeks, and to test out some configuration options I have setup a web server on my local network which I would like to be able to access ...
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20 views

On Cisco firewall, show access-list main rules only (with line numbers)

For example, if I do a sh access-list Lets say I have a rule on line 2 that has one object-group to another object-group connected on X ports. Well, there may be 30 lines below that, that all say ...
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0answers
28 views

MySQL on Ubuntu. 10061 error on 3306

A fresh install of Ubuntu inside of a Virtualbox with LAMP option selected. I am unable to connect to the server via telnet on this port or via ODBC from my host machine. I can ping and SSH both ...
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1answer
15 views

NRPE Firewall blocking xinetd

From one side, my nagios server, IP 10.1.1.232. Here is my Nagios's xinetd's NRPE config : # default: on # description: NRPE (Nagios Remote Plugin Executor) service nrpe { flags = ...
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29 views

iptables, ufw, and psad - scanned UDP port alerts from router and devices on home network

I have a fresh install of Ubuntu 16.04. I configured iptables, ufw (with gufw), and psad using instructions from https://www.thefanclub.co.za/how-to/how-secure-ubuntu-1604-lts-server-part-1-basics and ...
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2answers
53 views

iptables - access to port 3306 timeout

I cannot connect to mysql from a remote server. I have bind-address commented out but when I add rules in iptables to block other connections the requesting server's connection times out. I tried ...
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0answers
29 views

Transferring data to Active FTP server fails from DMZ but works fine from LAN

I know there are a ton of similar questions already, but I've read through just about everything I could find and am still having trouble resolving my specific issue. Problem: I am having difficulty ...
0
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1answer
39 views

Firewall rules for ssh, ftp and webapps

I'm running a small cluster with Centos 7 and want the following rules for firewall. Have ssh access from anywhere (i'm going to further configure that from /etc/ssh/sshd_config) Have ftp access to ...
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0answers
21 views

Does IKEv2 (Windows Client) require the client firewall to perform NAT-T?

I am kind of new to IPSec VPNs. I am trying to set up an IPSec implementation using libreswan with IKEv2 for road warriors. Being road warriors these clients will likely be behind their home ...
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0answers
70 views

FTP protocol Extremely slow on Windows 10. What could be causing this?

I am running 2 different devices (A pc and a laptop) both on the same network, both Windows 10. The laptop has standard transfering speeds on the FTP protocol. The PC has extremely slow transfer speed ...
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2answers
48 views

Check if iptables rules are working

I have three virtualboxs. 1) Virtual machine VM-A that works as a router with two interfaces: eth0 - 10.160.10.254 eth1 - 172.10.0.254 2) Virtual machine VM-B that works as an internal network ...
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26 views

netfilter, block port range [31000-32000] on public interface eth2

I need to block the port range [31000-32000] on my public interface eth2. Services can be accessed using private network interface eth3 I have tried : root@master-sbg-01:~/# iptables -A INPUT -i ...
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1answer
28 views

Issue in Accessing FACEBOOK site in Domain network

In our Domain,We have setup firewall to prevent unwanted access to the websites. But a weird thing is even network administrators(whose IPs are not blocked by firewall) cannot access to facebook site....
1
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2answers
55 views

RPC Server is unavailable while trying to promote a domain controller. Open firewall

So I've been scratching my head around this problem for a few days now. This is a quick schema of our infrastructure : Our Primary Domain Controller is running in an hypervisor, in our datacenter. ...
0
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0answers
27 views

How to isolate two containers connected to the same bridge?

I have several LXD containers which are bound to a single bridge (the default lxdbr0 or another one, it does not matter). The host itself has another two interfaces, one ultimately connecting it to ...
0
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1answer
43 views

IIS ftp server issue from command line

I'm trying to config an ftp server on IIS (Windows Server 2008 R2) I configured basic authentication with read,write permissions for a user and no SSL I also opened port 21 on server firewall then ...
0
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0answers
19 views

Iptables linux routing with 2 chain proxies

Im trying to setup a connection between a PCs in my local network, to foreign resource XYZ in a specific way. My network is currently configured like this: I have a pc behind the proxies -> Then I ...
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0answers
40 views

Not able to RDP to the VM which is part of new subnet in Azure virtual network

Here are my environment detail I am using Azure IaaS (Infrastructure as Service) I am having one vNet (Virtual Network) I have set-up site to site connectivity (on-premise to azure) I have one subnet ...
0
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1answer
163 views

OpenVPN Ubuntu Server Routing Problems No Internet

I'm running OpenVPN on Ubuntu 15.04. When I connect to the server, I can connect and authenticate correctly (I use PAM auth because I'm lazy). Once connected I can't ping the server or access the ...
0
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0answers
13 views

CSF Firewall unblock countries

I've a VPS Server running CENTOS 6.7 x86_64 with CSF Firewall activated. Sometimes I see in "Firewall Deny IPs" that blocks suddenly connections from my country (Spain) to some of my clients. Not ...
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0answers
30 views

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 ...
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1answer
45 views

How can I block access to the internet for static addresses?

I have a router on CentOS 7 which provides access to internet for several IP addresses, which are reserved at DHCP server. Other hosts are blocked. If someone put static address from the reservation ...
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0answers
75 views

ssh login timed out after enabling the ufw firewall ubuntu server

I followed digital ocean tutorial to enable the firewall in my ubuntu server. The steps I performed is: 1> change the port no to some other no. (8338) 2> enable firewall using sudo ufw allow ...
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0answers
20 views

Self signed Cisco VPN Certificate

So I just rented some servers protected with a Cisco Firewall from a data center provider. I plan on accessing these servers through VPN. The instructions from the data center provider was to ...
5
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0answers
78 views

IPset Alternatives and Firewall Management

I have CentOS 7, Plesk 12, 8GB RAM VPS. I have around 1000 rules in my IPtables to block abusive users. But when reloading IPtables it takes 15 seconds to reload all 1000 rules. First of all, is it ...
2
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0answers
42 views

Block incoming traffic in bonding mode when primary interface is down

My server running on latest kernel (4.4.6) has configured a bond device (bond0) with two enslaved interfaces eth0, wlan0 with primary interface eth0. cat /proc/net/bonding/bond0 Ethernet Channel ...
0
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1answer
45 views

Centos 7 network issue

I have a Centos 7 server behind a Dell sonicwall I have configured the sonicwall to allow certain services and this seems to work fine. However I can't telnet to some ports. I have added Wireshark to ...
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0answers
87 views

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: ...
0
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1answer
113 views

Firewalld blocks IPv6, ignores config

I'm trying to setup an IPv6 web-server on CentOS 7.2 with NGINX. I have tested my IPv6 connectivity outgoing and incoming - everything works. My IP, AAAA records, etc as fine as well. Essentially ...
3
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0answers
128 views

Hacker bypassing iptables

(moved from SO) I have iptables protecting a sip server. It blocks all IPs except ones I specifically opened, and it seems to work for almost everyone. I have tested from lots of ip addresses that ...
2
votes
1answer
37 views

IPTables Configuration to allow all connections, only close/deny once data is sent

I'm looking to set up my IPTables firewall in such a way that: Any new connect() is accepted Once data is received: If the destination port is on a whitelist, continue allowing the connection and ...
0
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1answer
31 views

Why is lfd prematurely removing blocks?

As you can see in the excerpted log file below (from /var/log/lfd.log), lfd is prematurely removing temporary blocks that it imposes on IPs: Apr 7 13:07:59 host lfd[32117]: (wordpressxmlrpc) Request ...
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1answer
81 views

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 ...
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0answers
66 views

Traffic on eth0 despite denying it with iptables

Despite having an iptables ruleset which should not allow it - DHCP is working on eth0. Given the below information can anyone give me an idea of why? tap0 is not up (not that it should make any ...
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0answers
47 views

PFsense 2.2.6 static dhcp hostname blank

We are on pfsense 2.2.6 and we enable static dhcp for each mac address on each VLAN where dhcp is enable. DHCP is working good but when I enable static dhcp and leave the hostname empty and when I ...
0
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0answers
26 views

firewalld multiple public ips to multiple private ips routing

I'm trying to use CentOS 7 server as a firewall/nat for some sensitive servers on the LAN. The CentOS server has multiple public IPs (one per box on the LAN) and I'm trying to associate each external ...
1
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3answers
38 views

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 ...
3
votes
1answer
27 views

Will it detriment my security if I allow all connections from localhost through iptables?

Under my current configuration, iptables will block every inbound connection, even if coming from localhost. In some cases, I need localhost to connect to itself. If I create a rule that allows all ...
1
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1answer
22 views

Failed to open a port in my ubuntu machine [duplicate]

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 ...
0
votes
1answer
108 views

CentOS port forward

I have the following situation: Internet ----- Server ------- virtual machine (kvm) public ip 192.168.122.12 x.x.x.x I need to make service on the port 3333 ...
0
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1answer
43 views

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 ...
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votes
1answer
31 views

Strange Firewall Placement? [closed]

I joint a company recently and manager given me a network design. I found that the network design is a bit different than normal cases. As I'm newbie on firewall. Does the below setting proper? They ...
3
votes
1answer
98 views

Reject all except for whitelist policy with firewalld

I've been reading on firewalld for about the whole morning, and I came up with the following public zone: <?xml version="1.0" encoding="utf-8"?> <zone> <short>Public</short> ...
0
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1answer
68 views

Firewall configured to allow 25/tcp but still cannot telnet into server on that port [duplicate]

I've got postfix and dovecot running on ports 25, 110, 587, 465, 993, 995 for the usual mail protocols. I can telnet into all ports except port 25 which you can see below. Any ideas on what's going on?...
6
votes
5answers
172 views

Adding second firewall to ISP connection with multiple subnets?

My routing knowledge is a little rusty. I have a fibre internet connection hooked up like this: The managed switch breaks out VLANS for transparent lan service that is also through the ISP's box. ...
0
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0answers
21 views

WCCP to Remote Cache Engine - Any limitations?

I am attempting to WCCP to a remote (cloud hosted) cache engine from an ASR 1900 series router that is performing NAT. According to my reading (which was mostly done on ASAs) the WCCP cache engine ...
2
votes
1answer
54 views

Only allow access to a port when connected to VPN

I am running a Centos 7 server with OpenVpn on an amazon ec2 server. How can I configure it to only allow access to ports 2087 and 2083 when I am connected to the VPN, but not when I am not connected. ...
2
votes
0answers
23 views

Allowing outbound internet access with NSX while maintaining micro segmentation

I am getting into the world of VMware's NSX product for the purpose of micro segmenting VM's in the datacenter. That is to say, living in the same network space but not being able to talk to one ...
0
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1answer
28 views

Reverse ssh for location distributed system behind firewall

We have multiple machines located in different area behind firewall which don't have Static IP and can't be accessible from the outside. We would like to access those machines but are wondering what ...
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1answer
113 views

Separate subnet with exceptions [closed]

I have a network with clients in the 192.168.30.x range and clients in the 192.168.40.x range. both are in a 255.255.0.0 subnet. All clients with .30.x are connected to one switch and all clients with ...