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

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Access Point Iptable/Route rule for allowing device discovery? Devices can connect manually, but not automatically. Multicast/Upnp issue?

I setup a wireless access point on my server and for some reason, everything works but automatic discovery features. I can't see any other devices, upnp devives aren't discovered, and I think it's a ...
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2answers
18 views

Is it safe to open all UDP ports range?

I've setted some main ports - 20, 21, 22, 23, 53, 80, 443 for incoming and outgoing TCP connections. If i want to connect from inside my server to another ftp server, it uses random UDP port in range ...
3
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1answer
7k views

Watchguard L2TP over IPsec passthrough

I'm attempting to connect to a VPN (L2TP over IPsec) server through (not to) a WatchGuard XTM 505 appliance. I have the VPN server setup behind the firewall on a 1-to-1 NAT, and other protocols (such ...
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0answers
10 views

Asking Questions for VPN, Firewall, and a NAS [on hold]

I sincerely apologize if this isn't the location it's supposed to be. My Sys Admin is dropping me in the ocean, and I need to ask some questions. Basically I'm going to a client's to ask some ...
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4answers
3k views

Sonicwall NSA2400 - No internet access

We've got a SonicWall NSA2400 configured with a LAN (X0) and a WAN(X1) interface. It was setup and working fine until just recently when a temporary worker changed some settings most likely NAT. We ...
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2answers
4k views

How to block all incoming request through one network interface?

Saying I have a linux server as a router from LAN to WAN. I don't want any incoming WAN request for safety issue. So how should I block all the incoming request through the WAN interface, but ...
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2answers
136k views

TCP/IP ports necessary for CIFS/SMB operation

If I want to allow Windows networked drives between two firewalled computers, do I need to open ports 137-139, or is port 445 sufficient? I have to submit a form and get approval to open firewall ...
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8answers
109k views

How to Unban an IP properly with Fail2Ban

I'm using Fail2Ban on a server and I'm wondering how to unban an IP properly. I know I can work with IPTables directly: iptables -D fail2ban-ssh <number> But is there not a way to do it with ...
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2answers
4k views

Configuring Fortigate OS4 for FTPS

I configured iis7 ftp to allow ssl connections. I set the ssl firewall to use ports 50000-50050. If I set up a custom service on my fortigate firewall for ftps with source ports 990-50050 and ...
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2answers
3k views

iptables block client ip internet access and keep LAN access

With the increase of appliances having network access and the potential for hacking, I want to block specific ip address from accessing the internet, but allow LAN access. For instance, I use a ...
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1answer
14 views

How can I check that the firewall is disabled for a TUN/TAP interface?

while trying to diagnose a UDP multcast issue on an OpenVPN client configuration and I've come across this block in the config file: # Use the same setting as you are using on # the server. # On most ...
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1answer
1k views

ZenOSS webinterface connecting

I'm having a problem with ZenOss. I installed the centos stack installer on Centos 5.5 x64. De installation succeeded and no errors where displayed. But when I tried to surft to the ip address it ...
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1answer
26 views

Strange activity on Wingate Proxy

I noticed some strange network activity on my network last night. I've never seen anything like it. It appeared as though public ip addresses were connnecting outward from my private network. It only ...
2
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4answers
19k views

VPN is working, except for DNS lookups. Firewall (Cisco ASA 5505) issue?

I've got the following set up: LAN -> DHCP / DNS / VPN server (OSX 10.6) -> Cisco ASA 5505 -> WAN Connecting to the LAN via VPN works fine. I get all the details properly and I can ping ...
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0answers
19 views

Windows server 2012, unable to access site in some ports from outside

We have our website hosted in a windows server 2012 server. Some staging sites are also hosted on same server in different port numbers like 5015, 5014. Now I wanted one more site to be added and ...
0
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1answer
1k views

How to unblock service discovery for IPv4 via Avahi?

On a Debian 6.0.6 system (squeeze) I am having trouble resolving a host using Avahi and IPv4. Here is a sample output: : nr@homedog 10102 ; avahi-browse -a + eth0 IPv6 yorkie [00:1f:3b:d8:67:1d] ...
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3answers
1k views

ping and traceroute does not work when UFW deny outgoing by default

How to make ping and traceroute work after setting UFW with deny outgoing by default? Here is my UFW configuration: sudo ufw status verbose Status: active Logging: on (low) Default: deny (incoming), ...
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0answers
9 views

Cannot communicate from VM instance in Google compute

We are using Google compute engine with a Gateway VM having public IP and couple of other VM's with private IP to host our test and production environment. All of them are running on Debian ...
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0answers
10 views

Firewall-Rules on Proxmox-Node cause VPS to be offline

I'm using proxmox to virtualize some small machines based on KVM. To do so I created the following network-config on the KVM-VPS: # This file describes the network interfaces available on your ...
14
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5answers
6k views

SSH from A through B to C, using private key on B

I'm looking for a simple way to SSH from my local machine, A, through a proxy, B, to a destination host, C. The private key that goes with the public key on C is on B, and I can't put that key on my ...
0
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1answer
2k views

Juniper SSG5 suddenly slow throughput

I'm trying to find out where in my configuration the problem might be. About a month ago we were easily getting 100 up 50 down through our provider through the Juniper SSG5. Starting a few weeks ago ...
0
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1answer
49 views

Router configuring without NAT

i just addes a fw to my network. it manages 2 WAN using load balancing.enter image description here a router i reached to configure, while the other no. in my netgear router i reset all settings, ...
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2answers
8k views

Windows Server 2012 Port Forward for Specifc Host

I am trying to have a specific host be redirected to another port when trying to access a service on port 80. So, when the client (192.168.1.22) requests a connection to the server (192.168.1.10) on ...
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4answers
20k views

Error applying iptables rules using iptables-restore

Hi I'm using Ubuntu 9.04 on a VPS. I'm getting an error if I apply a iptables rule. Here is what I have done. 1.Saved the existing rules iptables-save > /etc/iptables.up.rules Created ...
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1answer
1k views

How to find which local process is sending spam on a Windows Server 2008 server

I am managing a Win Server 2008 system with a number of hosted web sites. Recently I found that something was sending spam through our SMTP server. The logs indicate that the connections were being ...
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2answers
1k views

grep, count and sort iptables log to get IPs qty and DPT?

How can I grep count and sort iptables log to get IPs quantity and DPT? Like I used this oneliner to get top IP quantity. egrep -w "Invalid Packet" ipfirewall.log | grep -o ...
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1answer
1k 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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3answers
1k 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 ...
0
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1answer
23 views

frequent delay of 5-10 sec in sending commands from putty redhat. Why?

When we type a command from putty, it suddenly hangs for a period of 5-10 sec or more, but the commands are sent to terminal later. So seems to be a latency which occurs frequently. But, I might be ...
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0answers
69 views

open port 443 in a double NAT system

i'm new there, i hope you can help me i own a network so configured: 2 WANs <> router <> firewall <> LAN i use a double NAT system for a WAN, that has a static IP. i reach to navigate by ...
0
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1answer
2k views

Allow access to printer between interfaces on Cisco ASA5510

I have a Cisco ASA5510 where we have to separate networks on two separate interfaces. The networks should have nothing to do with each other except that network B needs to access a printer on network ...
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1answer
20 views

Telnet times out on local machine but works externally

Im trying to get inbound mail working with postfix. Nothing is showing up, even in the maillog. Outbound works perfectly, but inbound doesnt. If i use telnet from an external server over port 25, i ...
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0answers
52 views

Can't reach a Kubernetes service on a guest node

I have tried to run the guestbook example in Kubernetes Github repository but I can't reach this service from my local host. My test enviroment consists of two virtual machines (with CentOS7) ...
3
votes
1answer
17k views

How to monitor user activity with a sonicwall tz205?

How can I centrally monitor users' browsing habits using a Sonicwall tz205, and running on a windows network? I am looking for a report that will show me LAN user's ip address and websites/services ...
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2answers
2k views

Access print server through firewall?

At my workplace, we have two fiber networks setup, one for the business network and the other for process control (industrial manufacturing). On the business network, there is a standard print server ...
3
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3answers
2k views

How to enable firewall on Centos 7?

My firewall is currently inactive. systemctl status firewalld firewalld.service Loaded: masked (/dev/null) Active: inactive (dead) I used the following command to enable the firewall # systemctl ...
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votes
1answer
22 views

Open port 8082 on ubuntu for remote access

I need to open port 8082 on my linux box for remote access. I can access the application on port 8082 locally, but not from my other box. Ports 8080 and 8081 are accessible locally as well as remote. ...
0
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1answer
18 views

Connection between sql workbech on my Laptop and Mysql on Google cloud compute engine (not cloud sql)

Is there anyway to open a port 3306 between MySQL database running on compute engine in google cloud (not cloud SQL) and MySQL workbench running on your local machine to connect ? I was able to ...
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2answers
3k 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 ...
0
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1answer
17 views

Allowing remote connections to SQL Express

On Windows 2008 Server R2, I installed SQL Server Express 2014 successfully and enabled TCP/IP on the default port (1433) and also added an inbound firewall rule to add port 1433. The database option ...
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votes
1answer
8k 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 ...
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2answers
1k views

How to establish firewall rules that accepting 11211 port in intranet for memcached ( Fedora)?

I am new for fedora and backend. And i have a job recently, to build a game server via linode. The current setup is 2 linode + 1 nodebalancer, I have a memcached server on each linode and I have setup ...
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0answers
27 views

Setting Up Zerospam

Edit: I'm trying to open up port 25 for public access. My boss and I are at a loss. We are setting up Zerospam for a client of our and we can't seem to figure out how to configure it through ...
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0answers
15 views

Wifi, remote connection, mysql

I am having this really strange error on my connection to my mysql server from a remote host. It basically hangs out large queries with blob or throws the following Warning: Empty row packet body; I ...
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1answer
132 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 --> ...
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0answers
21 views

fedora 23 - firewalld blocks imaps smtps

I'm having a weird problem. I can successfully connect to dovecot and port 465 and 993 is open but I can't receive emails as long as firewalld is enables and started. What is going on?
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2answers
2k views

Smoothwall Express interface issues

I have a SmoothWall Express box that is currently configured with a Green and Purple interface. Both interfaces are in the same /24 subnet (which seems odd to me). The green interface (address of ...
0
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1answer
1k views

Can't connect VPN tunnel when other on same NAT-router is connected

We have recently changed our FW to a ZyWall 310 with drastically improved throughput over the old one. However there is a new problem that occurred, we have several L2TP/IPSec clients that connect to ...
0
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1answer
1k views

Juniper ScreenOS Windows 7 Vpn client

I'd like to configure my Juniper firewall so users can VPN from the windows built in client. Can anyone provide me with that information on how to go about configuring this? (I'm somewhat new to ...
2
votes
1answer
4k 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. ...