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

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5answers
7k views

Remote connection sql server not working but if firewall disabled it does?

I have setup sql server express 2008 on a windows 2008 server. And i have done all the standard stuff in sql to allow remote connections. The strange thing is if i disable the windows 2008 server ...
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0answers
37 views

UDP multicast stream on win server 2k8 R2

so i have 3 mega PCs with win 2k8 installed on them having: 1st) 1 internal NIC and 1 external 2nd) 2 internal NIC and 2 external 3rd) 2 internal NIC and 4 external same stream put on any NIC on 1st ...
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0answers
46 views

Dovecot/Postfix mail server replies to [SYN] with [RST, ACK] when user attempts to connect (POP3). Likely iptables?

Currently I am trying to trouble shoot an e-mail server that will allow users to send e-mail, but not log in to the server (POP3) or receive e-mail using their Outlook clients. Previously this was ...
9
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5answers
12k views

Disable Windows Server Network Locations

I'm not sure what exactly this feature is called. But in Windows Server 2008, it has the Vista Public/Private/Domain locations. This makes sense for laptops, and none at all for servers. My problem ...
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0answers
21 views

Fail over in Lokiwall Firewall

I have configured lokiwall firewall on my linux machine having multiple interfaces. Dual Routing works fine. However, I wanted to know how does the fail over happen in case a link goes down. Do the ...
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0answers
154 views

Force all traffic from one user through an OpenVPN tunnel on Debian 6 with iptables and ip route

I’m trying to force all traffic of one user through an OpenVPN tunnel. It is giving me grey hairs. The current situation is that I can either allow all traffic for this particular user, and it will go ...
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2answers
2k views

ufw blocking apt and dns

I installed ufw on my Debian system like the following: # aptitude install ufw # ufw limit 22 # ufw allow 80 # ufw allow 443 # ufw enable # ufw status verbose Status: active Logging: on (low) ...
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0answers
129 views

Secondary DPM server and access to protection agents at primary server

Disclaimer: This is not an ideal setup. In a perfect world we would have a direct two-way VPN between our site and the remote site. My task is to enlighten the consequences of running a System Center ...
1
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1answer
638 views

QoS settings for Wi-Fi calling on pfSense firewall/gateway?

The new version of iOS 8 as well as Android supports Wi-Fi Calling with multiple cellular providers including T-Mobile in the US. I am currently running pfSense as the primary Internet gateway for ...
0
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1answer
58 views

Do blocking input ports increases security?

1-Do blocking unused input ports in firewall increases system security? How? (as there is no daemon listening on those ports anyway) 2-Do dropping those unused ports will positively or negatively ...
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0answers
22 views

Using a Barracuda F400 Firewall Router Without a Modem

I'm looking into a problem where VoIP phones don't ring for some of the incoming calls that I believe might be due to the network configuration. Do you need a modem if you are using a Barracuda F400 ...
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0answers
51 views

Intermittent SSH problems with a specific server from a specific Wifi router

I've been ssh'ing into a specific server from my home office via Wifi and Time Warner Cable internet for years with no problem. In recent months, I started having problems, where I'd be unable to ...
38
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13answers
15k views

iptables Tips & Tricks

I'm sure Linux sysadmins are quite familiar with iptables, the userland interface to the netfilter packet-filtering framework. Now, this "Question" is meant to be a Community Wiki for collecting ...
1
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2answers
1k views

Configure Cntlm to use no proxy if none are available

I am behind a corporate firewall in the day, and on an open internet connection at night. I have configured cntlm to forward to my corporate proxy, but when I connect from an open connection, I must ...
0
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1answer
176 views

--utc option is not working in iptables

I am using iptables v1.4.7/8. I used the following command iptables -A INPUT -s 10.0.4.247 -m time --utc --datestart 2013-5-23T7 --datestop 2013-5-23T9 -j DROP my utc time date -u Thu May 23 ...
1
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1answer
192 views

Fail2ban jail.local vs jail.conf

Does jail.local file act as an override to jail.conf or as a replacement to jail.conf? When I was learning about Fail2Ban from tutorials, most of them usually say either to copy jail.conf to ...
1
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1answer
84 views

MySQL on LAN not working when IPTables enabled

I have two Centos VM. The IP Addresses are as follows : VM_1 => 10.99.0.10 VM_2 => 10.99.0.12 Apache and PHP are in VM_1 and MySQL is in VM_2. Both are having iptables rules. VM_2 is working ...
2
votes
3answers
5k views

FTP Active/Passive not working like I expect

So I've got an interesting issue at the moment. I'm attempting to use curl (7.15.5 on CentOS) to retrieve a file from a remote FTP server. Our client changed something last weekend, because it worked ...
1
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0answers
38 views

PF rule for Continuity

So it looks like the Continuity on OS X 10.10 creates network interface on the fly (utun2 here) and my PF blocks it, so that I can't make/answer calls. I'm not an admin, just use the IceFloor for PF ...
0
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1answer
82 views

Can I block inbound traffic from a certain ISP

The problem My server keeps getting DDoS attacks from IP's belonging to Ecatel in The Netherlands. I wrote them a month ago and still haven't heard anything, and keep blocking individual IP addresses ...
1
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2answers
175 views

Test port reachability from a remote host even though the port is not bound to a service?

I need to check whether a remote host is able to reach a specific port. At the time of test the service bound to that port will be down. The possible issues that the test would address would be : ...
0
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0answers
27 views

Publishing Multiple SSL Connections via TMG

I am using a Microsoft TMG 2010 as my Firewall. It is configured in a Three-legged approach, with public facing servers in DMZ. There are two public servers. Once is a Citrix Access Gateway which ...
0
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2answers
101 views

Cisco 887VA - Cannot open port 110

I am trying to configure a Cisco 887VA at work to open port 110, but no matter what I try, it doesn't seem to work. The router is accessed from within the building via a web UI but require CLI ...
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0answers
43 views

nslookup gives timeout based on request - what gives?

I have the following strange problem with the DNS lookups in our Windows domain (dns service runs on the domain controller): from machine 'A': dns request for machines in the same network zone ...
1
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3answers
15k 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
41 views

Making a server “read only” except for me (what the inbound/outbound rules mean)

I have an ec2 instance. It will start a webserver, and my public ip is myip. I ssh into my machine. What should incoming and outgoing rules? Why? I want only my ip to be able to change things on the ...
0
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1answer
59 views

Cisco PIX Firewall Version 6.3(5)

I am unable to ssh to any servers. I've exhausted every possible thing except the corporate firewall. Its an old cisco pix firewall. [model] Cisco PIX 501 I'm trying to figure out 1) how to ...
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0answers
58 views

How can I log and maybe even block IPs that send lots of incoming UDP traffic?

we run a voice / teamspeak server which receives legitmate traffic on port 9987 from many ips. Sometimes we get DDoSed. So people use single Servers and send 1-3 Gbits of UDP Floods to that port. This ...
0
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0answers
26 views

Smoothwall firewall seems to be preventing “large” uploads

One of our customers has a Smoothwall firewall at the edge of their network. External users should be able to use a mobile app to upload images. The images are sent as base64 encoded strings in a JSON ...
7
votes
4answers
11k views

Firewall blocking FTP server on Windows 2008 R2

I can access the FTP site without problems from the local machine, but it times out from the remote machine. If I turn the firewall off COMPLETELY, it works. Obviously, this isn't really a ...
0
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1answer
62 views

multi-wan problems with web services

I recently set up a multi-wan connection for a small company, because they are at the end of the line for any possible ISP, services do go down, and they really depend on their Internet connection. I ...
0
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1answer
62 views

iptables with sticky forwarding/routing

My iptables is sticking. I have a DNS server behind IPTables and down a NAT'ed OpenVPN pipe. Using tcpdump I see DNS packets hit the outside router but it takes 4 or 5 DNS query attempts before the ...
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3answers
1k views

Using a nat rule to translate 80/443 traffic to web server, but internal users cannot access it using external ip/domain name

I am using Cisco ASDM for ASA I have my internal network called soa. My outside interface is called outside. Let's say my outside IP given to me by my ISP isp is y.y.y.y I have a web server inside ...
2
votes
4answers
2k views

What could prevent one Amazon EC2 instance from pinging another instance's Private IP?

I have multiple Amazon EC2 instances which need to communicate using private IPs. However, so far I've been unable to ping one instance's private IP from another instance. I can ping external ...
3
votes
2answers
692 views

Applying outbound connection rules PER USER in Windows Firewall with Advanced Security

In the latest version of the Windows Firewall, included for example in Windows Server 2008 R2, you can block incoming connections and apply this rule only for a set of users (Users Tab in the rule ...
0
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2answers
82 views

IP rules misconfigured, lost access to server

I have to give my IP rule like, DROP if source is not from 127.0.0.1 AND destination is 9200 But unfortunately, I gave it like, DROP if source is not from 127.0.0.1 (missed the port) So I lost ...
0
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0answers
708 views

Virtualized endian firewall on VMWare ESXi - VPN Malfunction

we got a physical machine with VMWare ESXi 5.1.0 U1 hosting a virtual Endian Firewall 2.5.2 all is running properly. The NICs are configured as shown in this image: http://imgur.com/o4IXn2D We have ...
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votes
4answers
7k views

Checking sftp connectivity [closed]

I can connect to the remote server using following command... sftp abc@255.136.181.123 But this works from server A and if I use the same command on Server B it does not work. 1) What changes ...
0
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0answers
15 views

Sonicwall 250m bandwidth

We have an nsa 250m with the SonicOS Enhanced 5.9.0.2-107o version. Is there a way to manage bandwidth by group ? I'm already able to do this this by user with this method Firewalls => Access rules ...
1
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2answers
368 views

Websockets and Firewall

I asked this question on Stack Overflow first, but then I thought Server Fault could be a better place to post it. I have two WebSocket servers both running on different ports than 80 and 443. ...
3
votes
2answers
4k views

Reduce firewall rules by half - one iptables rule for tcp and udp

I have a number of iptables rules on my firewall that look like this: iptables -A zone_lan_forward -p tcp -d 1.2.3.0/24 -j ACCEPT iptables -A zone_lan_forward -p udp -d 1.2.3.0/24 -j ACCEPT Is ...
0
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0answers
22 views

netsh advfirewall : how to force to prompt matched IP

I have a netsh script that inserts some IP's to block in the Microsoft firewall. All these rules are working perfectly. I would like to create an additional rule to have a popup / prompt from the ...
0
votes
1answer
357 views

ufw seems to block all incoming connections when defaulting to block outgoing

I am currently trying to configure ufw on Ubuntu 12.04 but to my understanding it behaves oddly. i tried allowing just some services on a remote machine, denying everything else. I thought - anyway, i ...
1
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3answers
10k views

Blocking Team Viewer

I'd like to block incoming TeamViewer connections to my network, but at the same time to allow outgoing TeamViewer connections. So that users can't connect to their work PCs with TV (circumventing ...
0
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1answer
210 views

Restrict access to some addresses for some OpenVPN clients

I have a VPN server on FreeBSD to access a LAN in which there are several machines. Some of the LAN machines offer un-autenthicated services. I want some VPN clients to access only one of the ...
1
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2answers
4k views

Redirect private LAN traffic to internal server when DNS answers with external IP

I have a mikrotik RB2011 router/firewall. Inside the firewall I have a web server that has an private IP (lets say it's 192.168.1.5) On the WAN side of the firewall I have a static IP (assume it's ...
0
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0answers
65 views

Is the IP based filtering in Amazon EC2 enough to ensure security?

I am hosting a webserver using Amazon EC2 and want it to be accessible only from a particular IP. I have set up my security groups to allow connections from only that IP. ...
1
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3answers
4k views

ZyWall throughput - ZyWall USG 50 vs 100 vs 200

I currently have ZyWall USG 50 running and have disabled all services except the firewall. Although stated on the ZyXel web that the firewall's throughput is 100Mbit/sec I'm unable to get more than ...
1
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0answers
89 views

NoVNC being blocked behind firewall, how can I find the port being blocked?

We have an OpenStack cloud running internally and wanted to allow student's access to the NoVNC console from within Openstack's Horizon web panel. Everything work's internally however after adding ...
0
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0answers
84 views

Setting up a firewall to route between interfaces on a gateway

I've been trying to setup a firewall on my debian gateway with iptables. The gateway is connected to a a network 12.120.0.0/24 on eth0 behind a NAT and the subnetwork behind it is 12.120.4.0/24 eth1. ...