The ip tag has no wiki summary.
4
votes
1answer
187 views
Inserting a nat solution into a network while it's not the gateway
I have tried this a few different ways. Currently trying with pf on freebsd 8.2
I am trying to insert a nat solution into an existing network that will redirect traffic from an outside ip address to ...
1
vote
2answers
3k views
How can I get the address of my local machine?
I'm on a macbook running Lion. In Terminal I'm connected to my schools server with ssh. I navigated to a folder on the server and have a file I want to copy to my local machine, but I don't know what ...
2
votes
1answer
3k views
tcpdump: “packets captured” vs “packets received by filter”
We have a script which calls
tcpdump -v src host <IP address> and port <port number> >>out.txt 2>>err.txt -w capture.cap
on multiple IP-s while the other parts of the script ...
4
votes
2answers
774 views
How to build a gateway from my Linux OS
I want to configure my Linux so that it will be used as a network router (gateway). Can anybody give me some hints on this? (links are welcome!)
Thanks.
2
votes
1answer
4k views
Static route in Centos 6
Here is my route -n output:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 ...
2
votes
1answer
254 views
Should OpenVPN point to point tunnels be on different ports?
The OpenVPN cookbook shows an example for site-to-site VPN (3 sites). They configured each tunnel on a unique port:
site A to site B: 1194
site A to site C: 1195
site B to site C: 1196
The author ...
1
vote
4answers
1k views
script to scan ip range and return results in a certain format
This script scans IP's and returns a status of Up or Down. How can I alter it so it doesn't scan everything twice? As it sits it scans everything and returns the "Up" addresses only and then scans all ...
2
votes
1answer
822 views
Testing if a port was forwarded correctly in Ubuntu
I have a Ubuntu box connected to a wifi router. This wifi router is connected to a d-link adsl modem/router. I am preparing this Ubuntu box to run a server that will use some special ports in UDP and ...
25
votes
2answers
2k views
How does SSH connection survive a network restart?
From a Linux SSH shell, type /etc/init.d/network restart to restart the network service.
I expect my SSH connection to die since the network service goes down. But it doesn't. Very cool. But how does ...
7
votes
3answers
2k views
What's the last number in this ip address?
An IP address like this 223.248.0.0/24 or 223.248.0.0/16
What's the last number mean in the IP address (24 or 16 in the above example)? Is there a simple way to understand how to set the number ...
4
votes
2answers
242 views
How can I use one network port for VPN and the other for everything else?
My Linux machine has two network ports with two IP addresses. I want to use one port for my VPN and accounting, and the other port for other usages. How can I tell Linux not to allow any requests from ...
3
votes
1answer
232 views
What is the kernel doing when I bring a TUN/TAP interface up
I'm playing around with the TUN/TAP device on Linux.
I've created a simple program that creates a TAP interface and prints anything that is sent through it.
When I bring the interface up with
ip link ...
1
vote
2answers
220 views
Is it possible assigning an separate LAN IP to service/daemon?
I'm using pfsense for prioritizing traffic around LAN. It works well for specified port, IP, network, but I'm having a problem with torrent (transmission bittorrent) outbound connections. The outbound ...
2
votes
1answer
704 views
iptrace for linux: how can I trace full packet contents?
I normally use iptrace on our AIX servers to get packet traces but have recently found out that this doesn't work for other 'nix systems - namely Centos.
Does anyone know what the analog would be?
...
2
votes
4answers
1k views
How to get netmask from bash?
I want to get my netmask on Linux. It is outputted with ifconfig but I want to extract the string.
3
votes
1answer
187 views
Detecting multihomed machine
Is there a way to reliably detect whether or not a machine is multihomed? I'd like to be able to write a script that will return a true or false regarding that information. Thanks.
2
votes
2answers
134 views
How to deny rdesktop access to others?
Someone keeps trying to connect to my Ubuntu machine through remote desktop. Is there any way I can determine who it is, and permanently block access to my machine?
1
vote
1answer
389 views
Running vim on a remote Linux machine “freezes” OS X SSH connection
(cross-posted this from SuperUser as the question seems more relevant to this audience)
I am attempting to SSH to a Linux (Fedora 14) machine and then open up vim to edit a file, however on my new ...
1
vote
2answers
1k views
Make some virtual mac address
I want to make some virtual MAC addresses for my network adapter or wireless adapter, so I can connect to network with more than one IP address from one computer or laptop.
How can I do it? (I know ...
-1
votes
1answer
253 views
How to “grep -v” private/broadcast IPv4 addresses?
time nmap -n -iR 0 -sL | cut -d " " -f 5 | egrep -v "^10.*|^172.[16\-32].*|^192.168.*|^[224\-255].*" > RANDOM-IPS.txt
so the important part is:
egrep -v ...
4
votes
3answers
2k views
How to filter IPv4 and IPv6 addresses?
echo "1.1.1.1" | awk '/[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/ {print $1}'
How can I filter IPv4 addresses in a script, and how can I filter IPv6 addresses.
I mean more precisely then this so the oneliner ...
2
votes
1answer
273 views
static ip to a freebsd server
I have
Comcast cable <====> modem <===> router <===> freebsd server
My freebsd server is connected to wireless router via a network cable.
What I want to do is, to have a static ...
2
votes
1answer
343 views
Is it possible to use Internet Connection Sharing with DHCP?
I know it is possible to share an internet connection with another pc using ip-forwarding and masquerade.
Is it possible to set up the sharing computer as a DHCP server, so the settings (ip, gateway, ...
3
votes
1answer
527 views
How to set a static IP in Ubuntu
How do I set my computer to have a static IP in Ubuntu 11.04? The only two lines in /etc/network/interfaces are:
auto lo
iface lo inet loopback
I think usually when people do this they have a wired ...
4
votes
2answers
769 views
What tools do I need to intercept and change an incoming packet on a WP2-Personal wifi hub
Which tools should I research into to intercept a plain text packet, edit it and then continue it on it's way. I am using Ubuntu 11.04 and Backtrack 5; my wifi is WPA2-person encrypted. I need to edit ...
6
votes
3answers
311 views
SpamAssassin Under Linux VPS
I am getting bald with this guys:
On a Linux VPS (CentOS), I have setup a mail server (Exim+Dovecot+Clamav+SpamAssassin) but scanning mail for spam using SpamAssassin is proving to be a challenge.
I ...
3
votes
1answer
481 views
Two IP addresses assigned to the same machine?
I seem to be using two IP addresses on my PC. I use DHCP to get an IP address and then I statically set an IP address and activate it. ifconfig says that I am using the address given by DHCP but I am ...
-1
votes
2answers
665 views
How to generate random IP addresses
$ nmap -n -iR 0 -sL > RANDOM-IPS-TMP.txt
$ grep -o "[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*" RANDOM-IPS-TMP.txt |
egrep -v "10.*|172.[16-32].*|192.168.*|[224-255].*" > RANDOM-IPS.txt
egrep: Invalid ...
0
votes
2answers
545 views
Understanding tcpdump output on a linux router
My router has an atm0 interface and a VLAN (atm0.1) interface, atm0.1 has the WAN IP address.
When using tcpdump -i atm0, the packets captured are only outgoing packet (LAN to WAN).
05:34:19.504895 ...
1
vote
0answers
276 views
Wrong route taken on a network with two gateways [closed]
In the following output, why does vpn1 route pings to 10.100.0.1 instead of 10.100.0.112? 10.100.0.1 is a network gateway with no NAT; 10.100.0.112 is a dual-homed host with NAT enabled.
root@vpn1:~# ...
2
votes
2answers
1k views
What is kernel ip forwarding?
I have seen on many blogs, using this command to enable IP forwarding while using many network security/sniffing tools on linux
echo 1 > /proc/sys/net/ipv4/ip_forward
Can anyone explain me in ...
2
votes
1answer
286 views
Can't access HTTP contents, but HTTPS and SSH are fine
I'm having a weired issue wih my Fedora 14 recently. Many details involed. Let's start from this:
I've been using Fedora 14 for months, and recent few days, offten I can't access Internet for hours. ...
1
vote
3answers
563 views
How to set Internet Protocol properties using terminal?
When I set up a Virtual Machine with windows (using VMPlayer), I set the Network Connection properties from the VM settings from NAT to bridged. Then I proceed to set the following IP Properties in ...
2
votes
3answers
264 views
Port monitoring on GNU/Linux based NAT router
I am using a Ubuntu machine as a NAT router. How can I find out the following:
the ports on which the LAN machines are listening or communicating (both tcp and udp);
which local machines have ...
3
votes
3answers
652 views
Accessing a linux machine with a name (not ip address)
When I access a linux machine with sshfs, I take the following steps.
Get the ip address of the linux (the ip address is dynamically allocated to linux)
Run sshfs id@ip_address:/HOME_DIRECTORY
Can ...
1
vote
3answers
549 views
Connect my laptop through desktop to internet
I'm currently at work and our wifi is down. I usually connect my desktop to the internet through eth0 and my laptop connects through wifi.
I have an extra port on the back of the desktop (eth1) and ...
2
votes
3answers
2k views
Send duplicate packets over two Internet connections
I need to duplicate an RTP stream over two different (non-reliable) Internet connections.
On the receiver side, I will probably run a custom program that will use a buffer and rebuild the stream ...
3
votes
4answers
1k views
Sniffing packets through router
I would like to create a system like this.
The user would connect through a wifi network which would reroute all http requests and responses through the network card on a computer thus allowing that ...
4
votes
2answers
1k views
Can't ping broadcast
We're running four computers connected to a hub (yes a hub not a switch) on Fedora 13. They were installed using images from a colleague that has recently left us to go back to school, they may have ...
3
votes
1answer
1k views
avoid IPv6 link local address on interface
I have a setup with virtual Xen hosts connected to a set of VLAN-s. On Dom0, I have set up a bridge for each of my VLAN-s to connect DomU-s to. Bridges are set up in /etc/network/interfaces like ...
5
votes
1answer
835 views
IP to Country console command
Is there a console command that takes an IP address as an input and shows its geographical information like city, country, ISP, etc.?
6
votes
2answers
712 views
Measuring internet connection quality
I'm having WLAN trouble on my dualbooting win/linux laptop - the connection on linux side has occasional trouble, and seems somewhat slow and chunky. I would try to fix this issue by fiddling with all ...
2
votes
1answer
285 views
Redhat Enterprise Linux 4.7 - Ping problem
When I try to ping some of the IP addresses I get "connect: No buffer space is available" error. Also when I check /var/log/messages, there are some errors like as following
printk: 99 messages ...
4
votes
5answers
6k views
How to route specific adresses through a tunnel?
There are certain websites/services which I can only access from the subnet on which my server is located (think of the typical intranet scenario). Is there a way to transparently route traffic that ...
