I would like, from a C program, find the hardware MAC address of the default route path. With BASH I can do a 'route' find 'default and then an ifconfig and grep for 'HWaddr'. Are there C calls to do the same??
View 12 RepliesI am trying to find IP address. In a socket programming tutorial, I found :
Code:
$ nslookup localhost
command. It gives me a address. However, one colleague told me :
Code:
$ ifconfig
It also returns me inet_addr. But both are different. Kindly tell me the correct method to find IP address? I have also checked the /etc/hosts file but it says "localhost"
Having trouble getting my Netgear WNA1000 working thru wireless router. Have tried lots of suggestions from other threads to no avail. Someone suggested that th routing table isn't set correctly, so have been trying to use the follwing to make the proper entry in the routing table: sudo route add -net 192.168.0.1 netmask 255.255.255.0 dev wlan0
Result: error message stating with:
"route: netmask does not match route address"
followed by "Usage" instructions which tell me to do what I just did. Any ideas on how I can populate my routing table with correct entry for my wireless card? Not to complicate matters, but I temporarily turned off encryption on my router to eliminate that as a possibility until I get connected. So maybe it'still trying to connect via encrypted mode - do I need to turn off encryption on my (client) end?
Writing a program that finds the IP address of a host name. Sorry forgot to include the line numbers, but where the $$$ is where the syntax error is. The errors are syntax error before "{" token and syntax error before "if". I've looked throught the code for a couple hours and can't figure out what's causing it. The code is attached below.
#define WIN
#include <stdio.h>
#include <stdlib.h>
[code]....
Im an academic (university networks and security lecturer) studying/teaching network and operating system security, and inspired by the work of Hovav Shacham set about testing ASLR on linux. Principley I did this by performing a brute force buffer overflow attack on Fedora 10 and Ubuntu 9. I did this by writting a little concurrent server daemon which accidently on purpose didnt do bounds checking.
I then wrote a client to send it a malicious string brute forcing guessed addresses which caused a return-to-libc to the function usleep with a parameter of 16m causing a delay of 16 seconds as laid out in [URL] Once I hit the delay I new I had found the function and could calculate delta_mmap allowing me to create a standard chained ret-to-libc attack. All of that works fine. However .... To complete my understanding I am trying establish where I can find the standard base address for ubuntu 9 (and other distros) for the following, taken from Shacham:-
Quote:
[code]....
/proc/uid/maps gives me some information but not the base address ldd also gives me the randomised starting address for sections in the user address space but neither gives me the base address. Intrestingly ... when a run ldd with aslr on for over (about) 100 times and checked the start point of libc I determined that the last 3 (least significant) hex digits were always 0's and the fist 4 (most significant) where between 0xB7D7 and 0xB7F9. To me this indicated that bits 22-31 were fixed and bits 12-21 were randomized with bits 11-0 fixed. Although even that doesnt define the boundaries observed correctly.
Note: I am replicating the attack to provide signatures to detect it using IDS, and for teaching purposes. I am NOT a hacker and if needed to could reply from my .ac.uk email address as verification.
I have a server with 2 network cards. eth0 is used for all traffic and everything is working fine on this side. Eth1 is used for traffic to and from 1 ip address.
Lets say the ip address of eth1 is 123.123.123.10 and its gateway is 123.123.123.1. I need to pass all traffic to 123.123.123.20 through eth1. What command would i use?
My ISP has given me 3 IP addresses to use for the internet (76.148.200.3, 76.148.200.4 and 76.148.200.5).
If I do a "wget whatismyip.com" or netcat into another server, I am appearing as 76.148.200.3.How do I change my route (command line) in linux to route internet traffic through 76.148.200.5?
Code:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
code....
I'm working on a userspace application that needs to find if the kernel has a route configured for a particular destination address, and what port it would be routed from. I'm hoping there is a simple kernel call that will do this for me, but haven't been able to find it yet :-)
I don't want to actually send a packet to do this, just query the kernel if where it *would* send the packet if I did.
The only method I've come up with is to get the kernel routing table through rtnetlink then check each entry to see if it matches my destination address. I guess this will work (after one or two tries to get the logic right ;-) ) but I'd rather do a single call if there is one.
i wanaa to config tlenet server and did the steps to enable it
but when i try to connect to server this error show :
telnet : connect to address 10.0.0.100 : No route to host
telnet : Unable to connect to remote host : No route to host
[URL]
I have a question regarding OpenVPN. I have configured my own vpn server. It is in a private network 192.168.0.0. The ip addresses I am using for the vpn connection are in the 10.9.1.0 network but I want to connect my ovpn clinets to the 192.168.0.0 network. I read the manuals and I think the "push route" command will work for me, but I cannot understand fully the description of the command "push route".
# Push routes to the client to allow it to reach other private subnets behind the server.
# Remember that these private subnets will also need to know to route the OpenVPN client
# Address pool (10.8.0.0/255.255.255.0) back to the OpenVPN server.
;push "route 192.168.10.0 255.255.255.0"
;push "route 192.168.20.0 255.255.255.0"
So the questions:
1. These private subnets behind the server are routed from my vpn server or from another router
2. How these private subnets "know to route" the open vpn address pool, is this a configuration of the router for this networks (192.168.0.0)or ?
I'm trying to move away from using /etc/rc.local for adding routes I've added
IPADDRESS0=xxx.xxx.xxx.xxx
NETMASK0=xxx.xxx.xxx.xxx
GATEWAY0=xxx.xxx.xxx.xxx
to /etc/sysconfig/network/network-scripts/route-eth0 after doing 'service network restart' I'm do see the new route as described by directive above. However, I still do not see the default gateway that's supposed to be on my box. Where/how do I define the default gateway using the route-ethX method above?
I've been seeing a bunch of issues with the /etc/resolv.conf not picking up the nameservers for 3g connections, and managed to fix that issue using tips found here.. the one thing I m having a problwm with is my 3G USB modem not picking up a default route/gateway. I can connect using KNetworkManager, get an IP and nameservers, but.
[Code]..
And to top it all off, I cannot figure out what the default gateway should be from verizon to just write a script out myself that'll do it automatically.
I have the following network/server configuration:
[Code]....
How do I prevent eth1 from being able to overwrite the default gateway that eth0 has already set?!? I read that one can create route-* files in the /etc/sysconfig/network-scripts/ directory to setup static default routes.But those seems to require one to know the IP address of the gateway, but in my case the ISP's gateway is served via DHCP and so it could vary from day to day. Here are the contents of some of the relevant files:
[code]...
I have a static ip on my wired (eth0) connection. I thought I had it well set up in yast. In the routing section I do have my default gw coming up there, with the the right nw i/f (eth0) associate with it. However, when I boot up, y config seems to ignore that fact, and I have to keep goign to root and typing "route add default gw <mygwip>" each time, which is something I want to avoid. Isn't it odd that the route settings created by yast have no effect? If they did, the route would be set up on bootup and I would haven't to do that typing.
View 2 Replies View RelatedI'm currently struggling with the following problem: Connecting to a wired network with NetworkManager (0.7.1) is no problem at all: Everything is set up automatically, including the default route:
[Code]....
When I now add the route manually it works. But as soon as the cable is plugged in, the NetworkManager overwrites the routing table entry again (which makes it quite annoying). Does anyone know a way to avoid this behaviour?
I'm currently working with Ubuntu 10.10.I wanted to add a default route to a gateway named ppp0.I did it with the command> route add default ppp0It works ok. But then from time to time it suddenly stops and I have to go back again to the server and retype the command. I'm clueless as to why is it happening. I can assure no one is working at the server or doing anything over there.Does anyone know causes that might be triggering route default to stop working?Btw where is the best place to add this command so it will be executed automatically on start-up and without needing to login to the server?
View 5 Replies View RelatedI am attempting to run apache on my linux router while connected to a VPN. My default route is set to the VPN endpoint and I cannot control port forwarding at that end. I cannot seem to connect to any service that i bind to the eth0 interface. I believe that my iptables rules and OpenVPN are the source of the problem.
/sbin/iptables -t nat -A POSTROUTING -o tun1 -j MASQUERADE
/sbin/iptables -A FORWARD -i tun1 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
/sbin/iptables -A FORWARD -i eth1 -o tun1 -j ACCEPT
I'm trying to set up load balancing using iproute2 following this guide. I've got 4 dsl links as follows:
eth1 - 100.100.100.1
eth2 - 100.100.100.2
eth3 - 100.100.100.3
eth0 - 111.111.111.111 (main uncapped line)
eth0 is the default route, and eth3 is being used for something else. So what I want to do is load balance browsing between eth1 and eth2. I've added all of the routes in the LARTC guide, but the command to enable the load balancing:
Quote:
ip route add default scope global nexthop via $P1 dev $IF1 weight 1 nexthop via $P2 dev $IF2 weight 1 obviously involves creating a new default route. Since I'll be using Squid to push the traffic through the relevant line, how can I set up a load-balanced link for eth1 and eth2 without changing the existing default route on the server?
So I have two network Interfaces
eth0 - NAT behind a router
eth1 - Public IP
When ever I restart the machine, both interfaces pull a IP, but the it randomly chooses eth0 or eth1 to have the gateway. I want the gateway to be eth0 always.
[Code]...
Is there some file or setting I can modify in Fedora10 that will always choose 192.168.1.1 on eth0 as the default gateway?
In an attempt to get something that, well, you know, just works... I migrated a laptop to Karmic server today. Which works fine, except for one thing: when I use wvdial and a Huawei E160g USB modem to connect to the Internet (which is the only option out here in the sticks where I live) no default gateway is set. When I add one manually everything is fine, except that the default gateway keeps disappearing after a while (at irregular intervals, as far as I can see). Nothing appears in any logfile that even mentions the default route, let alone a reason for its magical vanishing trick. My wvdial.conf is fairly pedestrian:
[Code]...
What's going on here? I'm stumped. And the mighty Googlebrain doesn't seem to know, either. How do I get wvdial & friends to set the correct default route upon connecting? Given the fact that without a default route a PPP connection to a remote network is little use, I would expect this to be a standard feature and not something that I'd have to script a work-around for myself. But then, I have been wrong before. Secondly, and more importantly, why does my default route keep disappearing without a trace?
I have a home server running Lucid which basically runs our home lan, but I also wanted to be able to run transmission-daemon over an ipredator VPN connection completely independently of the ethernet port (as far as the application layer is concerned anyway). Most of the howtos for setting up VPN use the VPN as the default route, however I still wanted to run a webserver, dnsmasq etc, not to mention free bandwidth access to my ISP etc.
Thus, this howto. The ppp connection still tunnels through eth0, but as far everthing else is concerned my server has two independent network ports eth0 and ppp0 and applications use the default route via eth0 to our router unless explicitely directed down pppX. I assume that you already have transmission-daemon installed.
[Code].....
I ask your help to diagnose a problem. For business reasons I use a broadband internet connection via a mobile phone's connected via bluetooth [rfcomm]. Speed is not the maximum but it is more than sufficient for my work. For configuration of ppp I followed this guide Pon pulls up dialup, but I can't navigate also if resolv.conf and default route are correct. In addition I would like to use the NetworkManager that by default, does not see the device. I worked around the problem this way:
I modified the / etc / rc.local so that launch at boot time: # Rfcomm bind yes
After starting Lucid Lynx, bluetooth connects to the phone but NetworkManager does not see the modem.
When I run the connection manually, by: # Pon BluetoothDialup
NetworkManager sees the device, but can not use it because obviously it is locked by the ppp daemon.
So I close the connection with: # poff
Now NetworkManager sees the broadband modem via / dev/rfcomm0, dialup is performed properly. I can finally surf and just enable vpn with NetworkManager. all start automatically at boot, without the need to manually connect and disconnects the dialup to use, finally, the NetworkManager.
i have setup an open vpn server and when i connect to it the client pulls an IP and but not default gateway. My goal is to route all web traffic through the VPN... My config file looks like this...
Code:
dev tun
proto tcp
port 1194
ca /etc/openvpn/easy-rsa/keys/ca.crt
[code].....
In 11.3, if in "/etc/sysconfig/network/ifcfg-eth0" i set DHCLIENT_SET_DEFAULT_ROUTE="no" this seems to have no effect. If i start my box, the routing table has the "default route"-entry offered by a remote DHCP-Server. More Info: My Susebox has eth0 and eth1 and both network devices should use DHCP4. But from DHCP-offer on eth0 i want to use
* "offered IP-Adress for eth0"
* "offered NTP-Server"
* "offered Host-Name"
From DHCP-offer on the eth1 i want to use
* "offered IP-Adress for eth1"
* "offered DNS-Servers"
* "offered Default Route"
yesterday I installed openSUSE 11.2 on my laptop. But I'm having problem getting the wifi configured properly. During the installation I got the message "No network running" (which I also saw after the installation when using the network configuration module of YaST after switching from ifup to NetworkManager). After installation NetworkManager seemed to work fine, it detected my wifi card, found the network, and I could even connect to it. Then the problems began, no Internet connection. The first thing I tried was pinging Google which yielded an "unknown host" message. So I checked /etc/resolv.conf, to look for the DNS servers, which where missing.
I added them manually and tried again. Still no luck, so I started pinging my router, which worked, tried again pinging Google using one of there IP addresses, which failed. So I ran route to find out which routes where being used, this one gave an unexpected result, because it only showed the route to the local network (I'm not sure about the loopback one, because this was also a lot of times missing when testing):
[Code]...
I have been encountering this problem, not only on 10.4, but on older versions too: I use a wifi router to connect my laptop to the Internet, but sometimes I need to connect directly to another computer to move some files over GLAN. But Ubuntu's Network manager doesn't allow me to configure the eth0 interface without specifying a gateway (no gateway = grey submit button), but when a gateway is specified, it always rewrites the default gw specified already by the active wifi connection and returns back after unplugging the eth cable.
Of course this can be solved by a few route commands, but this is unacceptable since it is needed to establish the cable connection without any further assistance from within and as well without replacing the default gw and thus breaking the Internet connection. Is there, please, any possibility how to prevent Network Manager from replacing these routes?
I'm setting up a static IP address & I need to know the mac address of my 2 unbuntu machines? [8.04 & 9.10].
View 3 Replies View RelatedI'm looking for a way to get my IP address using the command prompt in Linux. I know when you type "ifconfig" you can get your local IP address (i.e. 192.168.0.103), but I'm looking for my IP address that I get from my ISP. How can I get this from Linux without having to visit some website?
View 3 Replies View RelatedMy Ipod got stolen a few days ago and I am trying to figure out its mac address so that i can track it. I have sshed into it several times and i found some logs for some of the sessions but I cant find its mac address anywhere. I am wondering is there a way i can figure it out with my ssh logs or some of my other logs?
View 1 Replies View Relatedwhen i send any packet to anu destination and want to see he mac address of source and destination i am using the command tcpdump -qec1 but rather then getting the mac address of source and destination each time i am getting mac address of the system which is broadcasting. will anybody tell me how can i get source and destination mac address even if any other packet is also being broadcast to my network.
View 1 Replies View Related