1
vote
0answers
16 views

Firewall and NAT settings in GSM modem for one server

I have a GSM Modem (PSI-MODEM-GSM/ETH) in field with one device behind, acting as a server. The situation is as follows: "PC" | \_________Dynamic IP: 10.103.153.122 | ...
-4
votes
2answers
35 views

How to manage PING replies? [on hold]

How can I manage, for example, my Ubuntu mashine so it doesn't (or does) respond to PING(ICMP ECHO_REQUEST - type 8) requests? Normally almost all computers in a LAN network responds to ping with an ...
0
votes
0answers
36 views

debian multiple network interface multiple networks

I have a virtual environment with 3 virtual machines on one host. One of my virtual machines has 2 network interface. I need the virtual machine with two interfaces to connect to two different ...
1
vote
1answer
20 views

Accessing a container from another container using the public IP of the host

I've some issues configuring properly the network in proxmox. In short, from a container, I can reach any web server outside (ex: google.com), but I can't reach the web server on my container. The ...
4
votes
2answers
157 views

packets sent on virtual IP don't hit iptables rule

I have a virtual interface eth1:3 with IP address 222.192.124.3, I have set up an iptables rule to log packets coming on that interface using the interface's IP (I know iptables doesn't care about ...
0
votes
1answer
57 views

Network remapping with iptables and PPTP VPN

I have two different networks: Home network 192.168.1.0/24 A - Home PC (192.168.1.100) B - Home Router (192.168.1.1 lan ip - x.x.x.x public ip) Office network 192.168.1.0/24 C - File Server ...
0
votes
0answers
15 views

Couldn't load target `DNAT':No such file or directory

Trying to do some ipv6 nat and running into an error from ip6tables $ip6tables -t nat -N IPV6-BRIDGE $ip6tables -t nat -A PREROUTING -p all -d 2600:3c01::f03c:91ff:fe6e:2563 -j IPV6-BRIDGE $ip6tables ...
0
votes
0answers
30 views

Pinging to google.com from a particular interface

I am connected to the internet via wlan0(wifi) and also have an ethernet port(not connected to the internet). I am looking for some iptables rule / route addition, which will let me do a ping via eth1 ...
-1
votes
2answers
57 views

Suspect traffic from 185.0.0.0/8 [closed]

I have a server/gateway running Debian 7. There is a big incoming traffic (for a homemade server) from an ip address located at 185.0.0.0/8 network for more than 40k packets in 24h. I have blocked all ...
9
votes
2answers
611 views

linux command to prevent dos attack by using netstat and iptables

I want to DROP more than 200 requests per ip to prevent ddos attack. this is command that i used to detect requests count per ip : netstat -alpn | grep :80 | awk '{print $5}' |awk -F: '{print ...
0
votes
1answer
40 views

Blocking incoming traffic for interface

I have created an interface eth0:2 and I want to make curl requests from that interface only so I want to block all ports and incoming traffic on that interface. This iptables rule used to work, but ...
0
votes
1answer
54 views

IPTables: Firewall with just one Eth device? [closed]

Admittedly I am a novice in the area of firewalls. But I have read on the IPtables and Firewall theory and command options. There is a general diagram by Rusty Russell, the creator of IPtables: ...
1
vote
0answers
26 views

OpenVPN running on Internet Gateway, so all private clients can access VPN with no config

Our LAN connects to our office gateway machine (192.168.1.1), which is connected to the Internet. I have setup NAT/Masquerading for this purpose with no issue. We also use OpenVPN to connect to our ...
0
votes
1answer
54 views

How can I configure iptables to forward and forget?

I'm trying to create a front controller where users can connect to a specific port and have their connection redirected to a different IP/port. The reason I'd like to be able to do this is for ...
1
vote
1answer
29 views

how to forward proxy requests using iptables

I've this schenario ----------------- ---------------- ---------- | SERVER A | ---(port:2128)> | PROXY | ---> | INTERNET | | (10.30.1.1) | ...
0
votes
1answer
66 views

Cannot close Port 25 after installing postfix

Before installing logwatch (which installs postfix) on Ubuntu 12.04, the port 25 is blocked by iptables/csf PORT STATE SERVICE 25/tcp filtered smtp After installing logwatch (which installs ...
-2
votes
2answers
35 views

How to block access to a local user to a local port?

How to block access to a local user to a local port? Example: user Elvis should not have access to the port 25600 on the same server.
0
votes
1answer
29 views

some outgoing http connections fail

After a recent reboot, my server is unable to connect via http, but not all the time. I have an accept rule for port 80, here is my iptables: Chain INPUT (policy ACCEPT) target prot opt source ...
0
votes
0answers
67 views

xen and port forwarding from dom0 to domU

I have a server running Xen with the following network configuration root@ubuntu:~# cat /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback auto xenbr0 iface ...
0
votes
1answer
33 views

How to access two separate web servers via a Linux Gateway running IP tables

I have two Ubuntu 12.04 servers. Server 1 acts as the firewall using IP tables and hosts the Proxy server. Server 2 hosts the web server. I have an external ip address terminating on eth1 on Server ...
3
votes
3answers
338 views

Can't stop DDOS [duplicate]

I need a little help dealing with ddos. I'm experiencing 1gb ddos attack on my server and I don't know how to stop it. (1gbs is the maximum speed of the server.) I've the following iptables rules: ...
1
vote
1answer
131 views

Access web server on VM from a machine in a different subnet

I cannot access to a web application running on a virtual machine hosted by KVM from a machine in a different subnet. So, I would like to access from the machine 192.168.1.2 (top right in green ...
0
votes
0answers
55 views

How to set mark on packet when forwarding it in nat prerouting table with rp filter 0?

I have a serious problem with my server ubuntu 13. I have two ADSL lines and an internal network as follows. i.imgur.com/v4ddHXf.png (URL IMG) IP redirections made ​​two because there are two older ...
1
vote
3answers
356 views

iptables error: unknown option --dport

The command iptables no longer recognizes one of the most commonly used options when defining rules: --dport. I get this error: [root@dragonweyr /home/calyodelphi]# iptables -A INPUT --dport 7777 -j ...
0
votes
0answers
78 views

Dropping packets with Open Vswitch and OpenFlowControl

I am trying to setup some Flows with ovs-ofctl to block all unwanted incoming packets for a VM. The commands I use are: ovs-ofctl add-flow xenbr0 "priority=65000, table=0, tcp, dl_src=*, nw_src=*, ...
0
votes
4answers
59 views

What can be done to migrate network applications when the client configuration cannot be changed?

We have a number of situations where a client application needs to be migrated from one host to another in an active production network. The servers continue to run other applications. The problem is ...
0
votes
1answer
80 views

Access Nginx by 127.0.0.1 works fine, but access by IP return 400

I deploy Django+uwsgi+Nginx project, but access nginx by 127.0.0.1 works fine, 400 returned if access by IP The iptables shows # iptables -L |grep 8181 ACCEPT tcp -- anywhere ...
0
votes
3answers
135 views

CentOS masqueraded network with iptables clients not connecting: Unable to ping

I'm a novice sysadmin working on a system with a CentOS server masquerading traffic with client machines also running CentOS. Something with the tables got messed up and my clients no longer have ...
1
vote
2answers
67 views

How to best redirect customers to a login page? (ISP)

I'm trying to come up with the cleanest way to redirect a user to a logon/payment page from an ISP gateway router. We run a small ISP and would like to force users to have to log in prior to getting ...
1
vote
1answer
110 views

Reach LXC container from a virtualbox guest on the same host

Context I develop websites on my Ubuntu laptop (Ubuntu 13.04 64b). Each site runs within a dedicated LXC container¹ on network 10.0.3.x I sometimes need to reach those sites from a virtualbox guest ...
1
vote
1answer
59 views

copy ipv4 rules to ip6tables

I have a static IPv4 and a static IPv6 address. Right now, my iptables look like: *filter :INPUT DROP [28:2168] :FORWARD DROP [0:0] :OUTPUT ACCEPT [551:134808] -A INPUT -i lo -j ACCEPT -A INPUT -i ...
0
votes
0answers
32 views

CONNMARK on rewritten packets

I have tried to ask this question on superuser, for it, being a custom setup, belongs there, but that got no answer even with a bounty. I have a host, on which I rewrite saddr and daddr of IP packets ...
0
votes
1answer
83 views

How to add another router on an existing subnet? [closed]

What I am trying to do is basically this. I am on a network who's routing table is something like this. Destination Gateway Genmask Flags Metric Ref Use Iface default ...
2
votes
1answer
158 views

LXC networking with public IP

I have installed LXC in ubuntu server 12.04 using this link. It was installed successfully and i am able login using ubutu/ubuntu as username and password. Then I tried to setup network for LXC ...
0
votes
2answers
40 views

Is it possible to force IP source depeding on source ports?

I have a question about routing. I've searched the internets, found some hints but couldn't make it work. I have a server with 2 public IP and the same gateway. Let's say 1.1.1.1 (on eth0) and ...
0
votes
0answers
23 views

Throttling bandwidth on a per group basis

I am wondering if it is possible to create a bandwidth shaping/throttling script that shapes traffic based on user group. That is, if user1, user2, are in user group group1, they will have 1mb/s ...
0
votes
3answers
61 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 & ...
0
votes
1answer
231 views

how to use iptables to block the IP of device connected to openwrt router

I have two routers(A,B).the A connect to internet with IP:192.168.1.1 The openwrt router B connect the lan of A by bridge with static IP:192.168.1.111. I am learning to use iptables to control the ...
1
vote
1answer
219 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
20 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
votes
1answer
63 views

How can I proxy ICMP requests?

I have a ubuntu server that receives many ping requests from various other servers in the network. I would like to be able to proxy these requests. Using iptable rules I can see how to DROP or ACCEPT ...
-1
votes
2answers
85 views

IPtables - opening ports not working

I am writing a script to open ports based on a textfile, and am having problems opening these ports. For instance, I have tried opening port 18819 by entering the command /sbin/iptables -A INPUT -m ...
2
votes
4answers
375 views

Linux - two subnets, one interface, one gateway - NAT the additional subnet

We currently have a few servers that all use the same LAN: Host1: eth0 10.0.0.1/24 Host2: eth0 10.0.0.2/24 Host3: eth0 10.0.0.3/24 Gateway: 10.0.0.254 We want to run some VMs (VirtualBox) on these ...
0
votes
0answers
60 views

can i forward internet from 2 public ip to 1 single private ip (network)? [duplicate]

I am rahul and i am new on centos 6. can anyone tell me .. is it possible suppose i have 3 nic cards in the same system and i have 2 nic cards for public ip(Eth1 and Eth2) and default Ethernet for ...
0
votes
2answers
207 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 ...
6
votes
1answer
1k views

Unexpectedly shrunk window

I run a major media upload/download site and I noticed these: Is this serious or background noise due to the big file sizes and is there any tweaks I can add to /etc/sysctl.conf to improve and ...
-1
votes
1answer
47 views

How to force traffic out to router when it is bound for another network interface inside the computer

I have a computer with two network interfaces, say eth0 and eth1 with IPes 192.168.1.10 and 192.168.1.11 respectively. Both these interfaces are connected to a router directly. When I send traffic to ...
0
votes
1answer
118 views

Enable route between subnet

I have a Centos server with three NIC cards. ETH0 Public IP xx.xx.xx.xx1/xx.xx.xx.xx2 (with two public IP) EHT1 Local Subnet 192.168.80.0 (DHCP server listening on this interface) ETH2 Local ...
0
votes
1answer
242 views

How do I configure routing from host system to virtual machine?

I have an Ubuntu host system that is running a MAC-VLAN virtual interface on top of eth0 interface, ipv4 routing is enabled. Also, this system has a Docker (LXC) container running: docker0 Link ...
2
votes
0answers
260 views

Limiting bandwidth with hashlimit (e.g. kb/s — not connections!) doesn't work, though the man page says it should

According to the iptables-extensions man page hashlimit can do bandwidth limiting: "flows exceeding 512kbyte/s" => --hashlimit-mode srcip,dstip,srcport,dstport --hashlimit-above 512kb/s ...