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

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297 views

Incoming traceroute blocked by ufw

One of my Proxmox VMs running Ubuntu 13.04 won't accept incoming trace routes while ufw is enabled. What command do give ufw to allow incoming traceroute(6)s? The following shows up in the syslog ...
2
votes
1answer
58 views

Request to server x Reply from server y

I need some advice from you guys: I'm dealing with a custom loadbalancer/software for which we will use 2 main servers and about 8 slave servers. In short: User sends request to main server, main ...
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3answers
73 views

How do I stop someone from saturating my line & wasting CPU cycles

My web host shows inbound & outbound traffic with mrtg. I have a steady 3.5mbps inbound traffic from Nigeria. Even assuming the source IPs & destination ports are blocked with Iptables & ...
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0answers
41 views

IPTABLES Limiting destination based on source?

I am trying to have a bridge firewall between my network and IPMIs. I want to be able to limit the allowable destinations, e.g. IP x.x.x.x has access to x.x.y.y and x.x.y.z but no others while IP ...
2
votes
1answer
665 views

How do I allow only certain IPSet set's to access a certain port with iptables?

I'm using IPSet to build IP ranges for different countries as follows : # Canada ipset -F ca.zone ipset -N ca.zone nethash for IP in $(wget -O - http://www.ipdeny.com/ipblocks/data/countries/ca.zone) ...
0
votes
1answer
1k views

iptables forward rule not working in openwrt

I am trying to apply some iptables forwarding rules in openwrt. Here is my scenario - My server has two cards ath0 and br-lan. br-lan is connected to internet and ath0 to private network. The other ...
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2answers
43 views

Is there a good way to prevent a server from emailing a specific address (we control both servers/apps)?

When testing a production app we occasionally need to pull from a live site and perform tests on a development server. There are quite a few email addresses stored in the database that we need to ...
1
vote
1answer
385 views

Mirror network packets from WiFi to Ethernet in an ASUS Router RT N53

I have an ASUS RT N53 router, running the default firmware (Linux 2.6.22 with busybox and uclibc). I need to capture data packets from some Wi-Fi devices I have connected to that router (iPad and some ...
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1answer
2k views

Open port 8009/tcp on Fortigate necessary?

A nmap scan of a Fortigate Firewall showed that TCP port 8009 open is. According to knowledge base articles this is only to download the client for ssl vpn. Is this port used for anything else, and if ...
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0answers
82 views

How can I use “show netstat” on a Sonicwall NSA 2400 correctly?

I have a SonicWALL NSA 2400 and I would like to view statistics on open connections. It seems there is a netstat command available via the serial console but It doesn't seem to work correctly. Once ...
0
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1answer
29 views

How do I specify the external IP when using iptables masquerade?

I'm using this rule to allow internet access through OpenVPN: -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE However traffic via the VPN is coming from the box's primary IP. eth0 has a /29 ...
0
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1answer
47 views

Reachability with OSPF on firewalled network

I'm trying to figure out how OSPF establishes routes when used on a network with firewalls. Say I have four routers (A, B, C, and D) and two firewalls (F1 and F2), arranged like so: (LocalA) A - F1 ...
0
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1answer
69 views

ASA 5505 - Outside IPs required for VPN Tunnel?

I've set up a Site-Site VPN and it seems the config is fine as the other site can establish the tunnel fine. The problem I have is that my side never tries to bring the tunnel up. Ping/telnet ...
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votes
1answer
70 views

No access to our server outside LAN

I hope this isn't above the scope of ServerFault. If the question doesn't work here, some direction would be helpful. We've got an Ubuntu development server with 2 nics. One has a public IP and one ...
0
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1answer
256 views

Adding a custom SSH port to Ubuntu 12.04 LTS through UFW

I am trying to configure a Ubuntu 12.04 based VPS and I have changed my ssh port from 22 to 803 and everything worked fine. After this I've installed UFW and now I can't login using SSH. Before I ...
1
vote
1answer
61 views

Outbound ports for a firewall for webserver and db server

I have an environment where there is one firewall, and there is a secure segment and a DMZ segment behind it. There is a bunch of servers in the secure segment - DB server, the QA server, etc and ...
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0answers
99 views

Why does firehol generate an iptables ACCEPT rule on top?

Firehol generates iptables rules from a convenient configuration file. In my /etc/firehol/firehol.conf I have the following very simple configuration to allow incoming connections on http, https and ...
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2answers
95 views

Collecting Web traffic and monitoring reports [closed]

My company is a med home health company and I have been tasked with seeing what people are doing on the internet. There's been a lot of people complaining of people shopping, surfing internet, etc on ...
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1answer
3k views

Fortinet multiple WAN IP to several ports

I have a 5 public IP address range. (ie: 1.1.1.1 to 1.1.1.5) I would like to assign the first to port 1 transparently in a way that a VPN router (RV082) could connect via it and respond ...
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2answers
1k views

force LAN hosts to go through proxy

I have an IPTables firewall on a Debian server, with a bunch of hosts behind it with masquerading. In the upstream network I don't have direct access to the internet, and I need to go through a proxy ...
8
votes
2answers
420 views

How to configure a small network of computers within a larger university network?

I have a small computer lab (8 HP workstations, 1 HP server, 2 NAS boxes, 1 HP networked printer) where currently all the devices are connected directly to my university's network. Each device has an ...
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1answer
198 views

ADSL Router - Access External IP internally

I have a problem when I'm doing an access using my DNS hosted at another server, which performs a redirect to my internal network. example: User attempting access to internal DNS: intranet.site.com: ...
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1answer
51 views

iptables allow A -> B:22 , B -> everywhere:22

I want iptables rules that let a server allow incoming ssh from a specific host and at the same time this server can connect ssh on any destination, then block any other in/out traffic Thanks in ...
0
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1answer
564 views

iptables Port Forwarding not working

I'm facing the problem, that my iptables rules aren't working anymore after I changed OS from Ubuntu 8.04 to Debian Squeeze. I'm trying to do a Port Forwarding by iptables -t nat -A PREROUTING -d ...
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1answer
63 views

Postfix maillog: warning: host nb-mx-vip1.prodigy.net[207 .115.36.20]:25 greeted me with my own hostname

Mail server on internal system, reachable through a gateway / firewall via forwarded port returned this error. I upgraded my environment (unadvisedly) with Fedora Core 19 and have had lots of ...
0
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1answer
170 views

Can't obtain ip-addres from my DHCP server

I can't obtain a ip-addres from my dhcp-server and it's going trough a firewall (pfsense), The firewall(pfsense) and DHCP server are two virtual machines on my physical server(ESXI). As rules i use ...
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votes
1answer
61 views

Can I use SSH tunnel to get around firewall? [closed]

I want to ssh to Server-A which only accepts connections on port 1234. This port is blocked on my current network's firewall. Server-B however, accepts ssh connections on standard port 22, and is ...
2
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0answers
377 views

How can configure Cisco ASA 5510 to allow access to Web server in DMZ from LAN with port translation?

I am trying to configure Cisco ASA 5510 firewall to allow access from LAN to DMZ web server. Web server is located in the DMZ and is using port 8080. I don't want users to type port number every time ...
0
votes
2answers
904 views

How to globally limit total number of TCP connections with iptables?

I'm having quite a difficult time figuring out how to REJECT both inbound and outbound connections from a machine with iptables once the total number of TCP connections hits a global maximum without ...
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votes
1answer
263 views

UFW rules for specific host / dynamic dns

How can I setup UFW (Uncomplicated Firewall) to add rules for specific hosts? Eg. I want to allow SSH only from yourpc.no-ip.org?
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1answer
738 views

alternative to forticlient for IPSec vpn? [closed]

our company has a fortigate firewall and we forticlient software. the software has many function like antivirus, parental contro, vpn etc. but we only use it for the vpn purpose. my question is there ...
0
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1answer
111 views

Securing database server with IPTables

I have my app (WordPress) and database (MySQL) on separate servers; they are connected on a private network provided by the hosting service provider, and I've taken all the preliminary steps (that I ...
0
votes
1answer
58 views

Is a reverse proxy useful behind a load balancer and IPS

We have a Web infrastructure with a farm of Web Servers. They are behind a loadbalancer which does SSL offload. We also have a IPS and obviously a set of firewalls. Now, for security reason we have ...
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2answers
109 views

How do I allow my server to ftp to itself?

I'm on RHEL6 and I'm trying to do an auto update on wordpress but the ftp and sftp connections fail. I suspect it's at least testing the connection from within the server which is not allowed by my ...
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0answers
549 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 ...
0
votes
1answer
49 views

Local network blocking our subdomain 'client.henrybuilt.com' [closed]

Do you have any idea why my local Seattle office network or firewall would be blocking my subdomain client.henrybuilt.com? All I know is: I can access it from anywhere other than the office network ...
3
votes
2answers
2k views

FTP - 500 I won't open a connection to xx.xx.xx.xx

I'm running a server on AWS and I'm connecting out to a partner's FTP site (not much idea what they are running). My server has an elastic IP. In the results below xx.xx.xx.xx is the internal IP ...
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votes
1answer
384 views

SSH and telnet in Hyper V [closed]

I have installed Windows server 2012 and setup a VM using Hyper-V. I have setup networking using a virtual switch on one of the NIC with address 10.0.0.20. I have assigned a static ip to Ubuntu VM ...
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votes
2answers
160 views

How p2p softwares(skype, torrent ..) work when Firewall doesn't accept incoming connections? [closed]

there's no policy from internet to local network in Juniper firewall, but softwares like skype an torrent work without any problem. without any incoming policy how do these programs work ?
0
votes
1answer
328 views

Asterisk behind a firewall

we have a bit a sticky problem on our Asterisk server, which we are struggling to resolve, I'm hoping someone with more knowledge than me can help. We are running Asterisk 1.8.23.0 on Centos 6.4 and ...
0
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2answers
47 views

making sure that iptables is running

Is there a tool for monitoring that iptables (or shorewall or similar) is up and running with a core set of important rules? I need something which alerts me either if the firewall goes donw ...
0
votes
3answers
268 views

What can we use as an alternative to IP whitelist in Windows Firewall?

We are currently using an IP whitelist in Windows Firewall to allow only certain machines to access Remote Desktop on our servers. Unfortunately, I have a new ISP now and my external IP address has ...
1
vote
1answer
93 views

How to specify Private/Public(non Elastic) IP address of an EC2 instance in the firewall/iptables of another EC2 instance?

I have two EC2 instances in same regions. Lets call them instance-1 and instance-2. instance-1 has an Elastic IP address attached to it but instance-2 does not. I want my instance-1 to allow inbound ...
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0answers
55 views

Firewall rules between windows cluster

I have been given the task to define firewall rules between 2 Windows clusters. The first cluster hosts a clustered middleware application and the second cluster hosts SQL Server. The 2 clusters are ...
1
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1answer
291 views

TS_Block and Windows 2008

I am running a Windows 2008 Server and I have installed ts_block on it to help block RDP brute force attempts on the server. Question 1: What I wanted to know is there any benefit for me using ...
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2answers
173 views

How to identify and differentiate networks so I can set location?

I am a developer and know just whatever sysadmin/networking/etc stuff I've picked up over a lifetime of computing and developing (not an inconsiderable amount, but I am very far from an expert on any ...
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vote
2answers
245 views

What on my EC2 CentOS vm is dropping ELB HTTP packets but not direct connections?

I've got a simple webserver (apache only) running on CentOS's AMI on AWS inside a VPC. I've got both AWS Security Groups and iptables opened up for port 80, with no source requirements. I then set up ...
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1answer
74 views

Is this CentOS 6.2 system reasonably secure as described? [closed]

This is a CentOS 6.2 system. For my login with the hosting company website, I set a 20-character mixed case, letters, numbers, symbols password and enabled two-factor authentication. In ...
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0answers
43 views

How can i manage bandwidht in linux router or firewall?

I have Linux server for internet sharing . i have 6 Mbps bandwidth, Now i want set 30Kbit to 40Kbit per user bandwidth. I want configure without proxy. It is possible that tc configration will ...
-1
votes
1answer
32 views

statistics on port 22 blocking [closed]

What are the statistics on port 22 blocking by firewalls in small and medium sized enterprises? We have a product that a customer installs on a PC, which communicates via ssh to our cloud server. It ...