A Firewall is an application or hardware device used to inspect and filter network traffic.
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When an IP or a block of IPs are assigned to you, do the network admins just add them to a router?
Let's say there is a router to the internet and a router separates your network from others within a data center.
When the data center provided gives you IP addresses, do they just take a [set] of ...
6
votes
3answers
566 views
What is the ip range of EC2
I'd like to setup a rule to block ssh request from EC2 since I've been seeing a large amount of ssh based attack from there and was wondering if anyone knew what their IP ranges are.
EDIT:
Thank you ...
6
votes
2answers
2k views
pfSense Firewall or Linksys/Cisco router for small offices
I'm about to start switching some networks around for multiple small offices. Each office has about 10 to 15 users and 10 to 15 computers. Each office has a spread of generic routers and access ...
6
votes
3answers
270 views
Is there already a recommended IPv6 Firewall setup?
I'd like to switch from private-IPv4-subnet-behind-NAT to IPv6, but of course I have no intention of exposing my users' workstations "unprotected" to the net.
Some obvious points up-front:
Allow ...
6
votes
2answers
5k views
Which ports do I need to open in the firewall to use NFS?
I'm running Ubuntu 11.10 - setting up NFS to share a directory among many other servers. Which ports are required to be opened on the firewall?
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3answers
931 views
Running a webserver behind a firewall, is it secure?
Currently we have a Linux-based firewall which NAT-ing our public IP address to give internet access to our staff's PCs and a Windows Server 2003 for internal filesharing.
I want to host Redmine/SVN ...
6
votes
4answers
2k views
What to do with an out-of-warranty Barracuda Spam/Web filter?
I'm working with an organization that would like to start using a old Barracuda Spam Filter 300 unit. I've sold and configured plenty of these, but was surprised to see that this unit's warranty ...
6
votes
2answers
387 views
Gigabit network with a 100 megabit firewall
We have set up all the equipment necessary to have a gigabit network. All servers + workstations are running gigabit cards, just bought a 16 port switch that can handle gigabit as well. My concern is ...
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9answers
2k views
Need prosumer router/firewall/vpn/vlan/nat advice [closed]
Looking for a recommendation on a device (or devices I guess) to do router/firewall/vpn/vlan/nat functons for my home network. Right now, I'm doing this with an IPCop box, but I'd prefer a little ...
6
votes
4answers
6k 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 ...
6
votes
1answer
1k views
iptables: difference between NEW, ESTABLISHED and RELATED packets
Part of a firewall on a server :
iptables -A INPUT -p tcp --dport 22 -m state NEW --state -m recent --set
iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --update --seconds 100 ...
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votes
3answers
753 views
OpenBSD/FreeBSD Firewall w/ GUI that is compatible with Intel 82574L Gigabit LAN NICs
I recently purchased a server to run m0n0wall or pfSense but I've learned since then that both of these firewall products are based on versions of FreeBSD which weren't yet compatible with the NICs in ...
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6answers
5k views
Linux equivalent of pfsync+carp for failover firewall/routing
I'm currently using a linux box to handle my firewall/NAT using iptables. It has two NICs, one link to a LAN switch, one to our egress Internet provider. I'm looking at upgrade this box to two boxes ...
6
votes
3answers
2k views
IPTables: allow SSH access only, nothing else in or out
How do you configure IPTables so that it will only allow SSH in, and allow no other traffic in or out?
Any safety precautions anyone can recommend?
I have a server that I believe has been migrated ...
6
votes
2answers
1k views
Block IP on EC2. Firewall or other options?
My EC2 (Fedora AMI) based service is being heavily hit by a rogue misconfigured client. What options do I have to block the IP of this rogue client?
6
votes
5answers
557 views
“No route to host” with ssl but not with telnet
I have a strange problem with connecting to a https site from one of my servers.
When I type:
telnet puppet 8140
I am presented with a standard telnet console and can talk to the Server as ...
6
votes
1answer
173 views
Cisco FWSM -> ASA upgrade broke our mail server
We send mail with unicode asian characters to our mail server on the other side of our WAN... immediately after upgrading from a FWSM running 2.3(2) to an ASA5550 running 8.2(5), we saw failures on ...
6
votes
2answers
1k views
Is there a secure way to allow IIS 7 in a DMZ to access a DB server behind the firewall?
Our network admins are adamant that it is insecure for our web servers, which are hosted in the DMZ, to access the DB server behind our firewall. To get round the problem, we access the data via web ...
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votes
5answers
1k views
DDoS Protection Services - are they good enough?
first of all, I understand that it's better to have DDoS protections on data center level. But our DC is not ready to provide good quality of protection. So we thinking about using some external DDoS ...
6
votes
3answers
2k views
Border firewalls and routing — static vs dynamic routing
Let's say you've got an enterprise with a small internet presence in the form of a DNS server, a web server, and a VPN server, all on the DMZ (in this case, an invisible pair of switches connected ...
6
votes
2answers
414 views
Linux iptables / conntrack performance issue
I have a test-setup in the lab with 4 machines:
2 old P4 machines (t1, t2)
1 Xeon 5420 DP 2.5 GHz 8 GB RAM (t3) Intel e1000
1 Xeon 5420 DP 2.5 GHz 8 GB RAM (t4) Intel e1000
to test linux firewall ...
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votes
9answers
2k views
Block users from Social networking websites while firewall is down
We currently have a SonicWall firewall, which does a pretty good job a blocking Social networking websites like Facebook and Bebo. The problem we are having is that sometimes we need to temporarily ...
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votes
3answers
5k views
Hardware alternative to PfSense software Firewall/Router
I have been using PFSense on a PC for about 4 years now for my home network, and it works perfect. I love all of its features and I really cannot complain.
Recently though I have been getting tired ...
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votes
6answers
4k views
Why block outbound ICMP?
This question is slightly related to "Why Block Port 22 Outbound?". I don't see how this can be a notable security risk.
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9answers
15k views
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2answers
689 views
tcp flags in iptables: What's the difference between RST SYN and RST and SYN RST ? When to use ALL?
I'm working on a firewall for a virtual dedicated server and one of the things I'm looking into is port scanners. TCP flags are used for protection. I have 2 questions.
The rule:
-p tcp ...
5
votes
2answers
168 views
What is an “application firewall”?
Trying to find out more about apple's "Firewall". What exactly is it?
In /usr/libexec/ApplicationFirewall
there are a bunch of undocumented programs, I've wandered through the mystery maze of ...
5
votes
1answer
565 views
Cannot modify iptables on CentOS
My question: How to add a custom iptables rule to accept connection on a certain port?
I'm trying to open port 3500 on my server but failed.
I started by using this command: (From ...
5
votes
1answer
7k views
Can I use ufw to setup a port forward?
Im currently using ufw to enforce some basic firewall rules. Is it possible to also use ufw to do port forwarding?
Specifically im wanting to forward incoming traffic to my server (same machine ...
5
votes
5answers
713 views
NAT as a firewall
Network Address Translation ( NAT ), seems to sort of act as a firewall for the hosts behind it because they are not available. Although I would never rely on this as my firewall, what are its ...
5
votes
4answers
1k views
Home Network, router firewall vs Windows firewall [closed]
Similar to these questions:
What Firewall Rules Should Be Used For A Home-Based System and
Firewall on VPS Use Windows Built In
But more specifically I'm guessing that using both the Windows Firewall ...
5
votes
3answers
447 views
How can I block a specific type of DDoS attack?
My site is being attacked and is using up all the RAM. I looked at the Apache logs and every malicious hit seems to simply be a POST request on /, which is never required by a normal user.
So I ...
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votes
3answers
1k views
Rate limiting with UFW: setting limits
UFW's man page mentions that it can setup iptables rate limiting for me:
ufw supports connection rate limiting, which is useful for
protecting
against brute-force login attacks. ufw ...
5
votes
1answer
122 views
Do you have to have two servers to put Exchange 2010 on the Internet?
I was reading about the Edge Transport Role on Exchange 2010. It looks like this is the only way to put Exchange the Internet. Is this true? Also, doesn't this require a second hub transport ...
5
votes
4answers
344 views
iptables: change policy or use catch-all rule?
What do you do when setting up iptables: change the default policy (iptables -P INPUT DROP, for example) or add a catch-all rule at the end of the ruleset (iptables -A INPUT DROP)? If you do prefer ...
5
votes
6answers
749 views
Advice a good hardware firewall
Which firewall would you advice to use to meet following 1Gb line and most anti hacking modules. Price range 10k-15k$.
3 years warranty on site, full support online.
About modules, i don't know what ...
5
votes
2answers
3k 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 ...
5
votes
3answers
810 views
Firewall still blocking port 53 despite listing otherwise?
I have 3 nodes with virtually the same iptables rules loaded from a bash script, but one particular node is blocking traffic on port 53 despite listing it's accepting it:
$ iptables --list -v
Chain ...
5
votes
2answers
180 views
Portable firewall rules for Linux and Free/Net/Open/DragonFlyBSD
I need apply the same rules (lists of IPs with allow and drop rules) in firewalls of Linux and *BSD. Do you know some application (CLI) for to convert a list of rules in the specific format of each ...
5
votes
1answer
1k views
Why is pfSense blocking multicast traffic when it is explicitly enabled?
I have a pair of pfSense firewall/routers set up in CARP/XML Config cluster. On the LAN side, the switch also has a pair of servers running corosync/pacemaker/drbd. These are on a different ip ...
5
votes
2answers
1k views
psexec Windows Server 2008 Firewall
I am trying to use psexec to run a program on my windows server 2008 boxes. It returns with the message "Can't access myserver: The network path was not found."
If I turn off Windows Server ...
5
votes
2answers
8k views
Cisco ASA5510 Bandwidth Shaping/Limiting
This question is in two parts:
Shape
How can I limit the bandwidth on a ASA5510 to less than 10Mbps?
Currently I have:
policy-map shape_policy
class class-default
shape average 9000000 36096
!
...
5
votes
1answer
188 views
Block Google requests to 16k using pf firewall
I'd like to block access to Google search using PF after the threshold of 17500 requests (connection established) in 24h, from a host running FreeBSD 9.
What I came up with, after reading pf-faq is ...
5
votes
2answers
574 views
Storm Botnet on Linux?
We have a customer who is running an office CCTV system which he accesses from home. The system runs on an embedded Linux box behind a NAT firewall forwarding to ports 8080 for web browser access and ...
5
votes
1answer
393 views
Cisco ASA Config for PCI Compliant Office
We have a small business office, but due to PCI compliance we need to segment this into two internet networks (one 'compliant' and one for any other devices to use).
We currently have a Draytek ...
5
votes
2answers
226 views
Is there a way to run FTPS on Windows Server 2008 / FTP 7.5 through a Firewall?
I'm attempting to setup a FTPS server on Windows Server 2008. The inner workings have been successful -- I can connect locally or on the VPN. But I can't seem to craft the firewall rules to make it ...
5
votes
2answers
863 views
Linux fails to interpret ACK, keeps resending SYN+ACK
The following is a wireshark dump of the problem occurring, IP-adresses replaced with 'client' and 'server':
4414.229553 client -> server TCP 62464 > http [SYN] Seq=0 Win=65535 Len=0 MSS=1452 ...
5
votes
3answers
6k views
Firewall rule to allow access to windows updates or other resources on a CDN?
What's the best way to poke a firewall hole in a border firewall to allow windows updates?
As far as I can tell, the windows update sites are hosted on a content distribution network that can ...
5
votes
1answer
425 views
iptables: building a rule set against abuse for DNS amplification attacks
I have been working on building a rule set to detect and block a DNS amplification attack.
I got stuck and am hoping to find help here.
I'll post here what I have (bash scripting, the portions that ...
5
votes
2answers
659 views
How should I set up my Hyper-V server and network topology?
This is my first time setting up either Hyper-V or Windows 2008, so please bear with me.
I am setting up a pretty decent server running Windows Server 2008 R2 to be a remote (colocated) Hyper-V host. ...
