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Do MTU modifications impact both directions?

ifconfig 1.2.3.4 mtu 1492

This will set MTU to 1492 for incoming, outgoing packets or both? I think it is only for incoming

Setting variable in bash -c

I try to set variable which get interface ip-address from ifconfig and read it later. But when i execute a echo command, variable still empty. Please look at my code:

/usr/bin/bash -c "HOST_IPS=$(/usr/bin/ifconfig | /usr/bin/awk 'BEGIN {cnt=0} {if($0 ~ /inet / && cnt==1) {print $2} cnt++}'); echo $HOST_IPS"

But /bin/echo work fine with same command:

/usr/bin/bash -c "echo $(/usr/bin/ifconfig | /usr/bin/awk 'BEGIN {cnt=0} {if($0 ~ /inet / && cnt==1) {print $2} cnt++}')"

ifconfig and interfaces [closed]

just a question for my understanding. on my mac when I use ifconfig command on my mac I get the following interfaces:

• en0
• en1
• lo0
• fw0
• vment0
• vment1

I don't understand why there are so many. I understand that eth0 would be for LAN connections, and that en0 is the wireless connection. But macbook only has one airport..so why en1 as well? not sure what vments are for either.

Parse ifconfig to get only my IP address using Bash

I want to edit the bashrc file to have a simple function called "myip" to run. As you might guess, the function myip prints only my internal IP address of my machine.

The far as I got working, this is the script:

ifconfig en1 | awk '{ print $2}' | sort

Which got my this output:

10.0.0.12
options=1<PERFORMNUD>
flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST>
fe80::daa2:5eff:fe96:ba2f%en1
d8:a2:5e:96:ba:2f
autoselect
active

I'm working on Mac OS X.

How can I get this done?

How to use pipe to parse output of a command

I want to process the output of a process, say ifconfig. As you all know output of ifconfig is a list of lines containing inet addr: mask: etc. But I want to extract the ip alone[from inet addr: field] and list it. is it possible with pipe command? like

ifconfig | What should be here?

I want the output of this command as list of inet addresses (of different access points if present).

Ionic mobile browser testing is not working

I try to use mobile browser testing with ionic. I'm connected in the same Wifi as my iPhone and checked my IP-Address with the following command: ifconfig |grep inet. When I'm running ionic server with the command ionic serve I'm not able to open my ionic app on my iPhone using my IP-Address and the specified port from ionic. Do I have to enable something else on my machine? I also tried different ports without any success.

How to I get the primary IP address of the local machine on Linux and OS X?

I am looking for a command line solution that would return me the primary (first) IP address of the localhost, other than 127.0.0.1

The solution should work at least for Linux (Debian and RedHat) and OS X 10.7+

I am aware that ifconfig is available on both but it's output is not so consistent between these platforms.

Retrieveing eth0 ipv6 address on linux

I'm looking to use my eth0 ipv6 address in one of my shell scripts. I could retrieve it using ifconfig and grep, but I'm certain that it must be somewhere in some text file I'm not seeing, which would ultimately make it much easier to retrieve. Anyone know where I should look?

Thanks

add and remove IP addresses to an interface using ioctl or netlink

Is there anyway to add and remove IP addresses from an interface (like loopback) in C?

I found ioctl and a few documents explaining how to do that (e.g. this link), however they are all for setting addresses not adding and removing?

Following the suggestions I ran strace for adding a new loopback and here is the results:

$ sudo strace ip addr add 1.2.3.4 dev lo
execve("/sbin/ip", ["ip", "addr", "add", "1.2.3.4", "dev", "lo"], [/* 17 vars */]) = 0
brk(0)                                  = 0x1bab000
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f221ed04000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=109414, ...}) = 0
mmap(NULL, 109414, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f221ece9000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libdl.so.2", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340\r\0\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0644, st_size=14768, ...}) = 0
mmap(NULL, 2109704, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f221e8e0000
mprotect(0x7f221e8e2000, 2097152, PROT_NONE) = 0
mmap(0x7f221eae2000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x2000) = 0x7f221eae2000
close(3)                                = 0
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or directory)
open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200\30\2\0\0\0\0\0"..., 832) = 832
fstat(3, {st_mode=S_IFREG|0755, st_size=1811128, ...}) = 0
mmap(NULL, 3925208, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f221e521000
mprotect(0x7f221e6d6000, 2093056, PROT_NONE) = 0
mmap(0x7f221e8d5000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b4000) = 0x7f221e8d5000
mmap(0x7f221e8db000, 17624, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f221e8db000
close(3)                                = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f221ece8000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f221ece7000
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f221ece6000
arch_prctl(ARCH_SET_FS, 0x7f221ece7700) = 0
mprotect(0x7f221e8d5000, 16384, PROT_READ) = 0
mprotect(0x7f221eae2000, 4096, PROT_READ) = 0
mprotect(0x638000, 4096, PROT_READ)     = 0
mprotect(0x7f221ed06000, 4096, PROT_READ) = 0
munmap(0x7f221ece9000, 109414)          = 0
socket(PF_NETLINK, SOCK_RAW, 0)         = 3
setsockopt(3, SOL_SOCKET, SO_SNDBUF, [32768], 4) = 0
setsockopt(3, SOL_SOCKET, SO_RCVBUF, [1048576], 4) = 0
bind(3, {sa_family=AF_NETLINK, pid=0, groups=00000000}, 12) = 0
getsockname(3, {sa_family=AF_NETLINK, pid=6804, groups=00000000}, [12]) = 0
sendto(3, "\24\0\0\0\22\0\1\3\214;\367P\0\0\0\0\0\0\0\0", 20, 0, NULL, 0) = 20
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"\344\3\0\0\20\0\2\0\214;\367P\224\32\0\0\0\0\4\3\1\0\0\0I\0\1\0\0\0\0\0"..., 16384}], msg_controllen=0, msg_flags=0}, 0) = 2000
brk(0)                                  = 0x1bab000
brk(0x1bcc000)                          = 0x1bcc000
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"\24\0\0\0\3\0\2\0\214;\367P\224\32\0\0\0\0\0\0\1\0\0\0I\0\1\0\0\0\0\0"..., 16384}], msg_controllen=0, msg_flags=0}, 0) = 20
sendmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"(\0\0\0\24\0\5\6\215;\367P\0\0\0\0\2 \0\0\1\0\0\0\10\0\2\0\1\2\3\4"..., 40}], msg_controllen=0, msg_flags=0}, 0) = 40
recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"$\0\0\0\2\0\0\0\215;\367P\224\32\0\0\0\0\0\0(\0\0\0\24\0\5\6\215;\367P"..., 16384}], msg_controllen=0, msg_flags=0}, 0) = 36
exit_group(0)                           = ?

Reading the output of a terminal command in java with BufferedReader

Noobie at java just starting, would appreciate any help. So my code is this and for some reason I cant get the output to work..I ve been sitting at this for hours..

package askisi1;

import java.net.*;
import java.util.*;
import java.lang.*;
import java.io.*;


public class Main{

public static void main(String[] args){

    try{

        String command = "ifconfig eth1 | grep -oP '[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}'";
        Process child = Runtime.getRuntime().exec(command);

        System.out.println("So far so good");
        BufferedReader r = new BufferedReader(new InputStreamReader(child.getInputStream()));
        String s;
        while ((s = r.readLine()) != null) {
        System.out.println(s);
        }
        r.close();
        System.out.println("Continue..");
    }
    catch (IOException e) {
        e.printStackTrace();
    }
}



} 

Solaris: Programmatic interface to ifconfig?

I'm looking for a programmatic interface to the Solaris ifconfig(1M) command.

Apparently Linux has the getifaddrs(3) command, but as far as I can tell this has not been ported to Solaris.

Short of attempting to use the code at the link above, is there any way to determine ifconfig(1M)-type data (network interface presence, state, etc.) without forking the system command and parsing the output?

Extracting an IP address to a variable using Expect script

Hi I am new to Expect scripting, and I have been trying to fetch an IP address into a variable using following :

set timeout -1
spawn $env(SHELL)
match_max 100000
send "ifconfig | grep -A 1 'eth1' | tail -1\r "
expect -re "inet addr:.* " {send "ping $expect_out(0,string)\r"}
send -- "exit\r"
expect eof

The problem is that it is trying to ping with the result of the ifconfig command which has some string characters in it.

Could anyone help me to extract just IP address from the ifconfig command and store it in a variable? I have been using $expect_out(buffer) as well, but just couldn't get my head around it. Any help along these lines would be much appreciated.

Bind outgoing traffic to eth0 instead of eth0:1

We added a second IP-Adress to a linux (debian) machine to implement a second SSL-certificate to a new Apache vhost.

Our ifconfig now looks like this:

eth0      Link encap:Ethernet  Hardware Adresse 00:0c:29:1b:ab:6c
          inet Adresse:999.999.999.39  Bcast:999.999.999.63  Maske:255.255.255.192
          inet6-Adresse: (...)/64 Gültigkeitsbereich:Verbindung
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metrik:1
          RX packets:219336884 errors:0 dropped:0 overruns:0 frame:0
          TX packets:223169420 errors:0 dropped:0 overruns:0 carrier:0
          Kollisionen:0 Sendewarteschlangenlänge:1000
          RX bytes:1971307659 (1.8 GiB)  TX bytes:713489565 (680.4 MiB)

eth0:1    Link encap:Ethernet  Hardware Adresse (...)
          inet Adresse:999.999.999.40  Bcast:999.999.999.63  Maske:255.255.255.192
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metrik:1

Problem: All outgoing traffic (MySQL connections to external DB-server, outgoing SMTP connections from postfix) now seems to leave through eth0:1, hence the second (new) IP 999.999.999.40.

How can we force all outgoing traffic to leave through eth0, IP-adress 999.999.999.39?

Output of route:

[n1 ~ #] route
Kernel-IP-Routentabelle
Ziel            Router          Genmask         Flags Metric Ref    Use Iface
localnet        *               255.255.255.192 U     0      0        0 eth0
10.10.10.0      *               255.255.255.0   U     0      0        0 eth1
default         gateway4.XXX    0.0.0.0         UG    0      0        0 eth0
default         gateway4.XXX    0.0.0.0         UG    0      0        0 eth0

Found solution:

Thanks for your hints, ip route was the way to go, now it works as desired.

ip rule add from 999.999.999.39 table t1
ip rule add from 999.999.999.40 table t2
ip route del default via 999.999.999.1
ip route add default 999.999.999.1 dev eth0 table t1
ip route flush cache

How to get an output formatted as "Interface: IP Address" from ifconfig on Mac

I am trying to get the following formatted output out of ifconfig:

en0: 10.52.30.105
en1: 10.52.164.63

I've been able to at least figure out how to get just the IP addresses (weeding out localhost) with the following command, but it's not sufficient for my requirements:

ifconfig  | grep -E 'inet.[0-9]' | grep -v '127.0.0.1' | awk '{ print $2}'

Thanks!

Bash script issue

I can run this command fine, with the output I want:

ifconfig eth0 | grep HWaddr | awk '{print $5}'

However, when I set the command to a variable, and print the variable, I get an error:

CASS_INTERNAL=`ifconfig eth0 | grep HWaddr | awk '{print \$5}'`
$CASS_INTERNAL

my internal xxx ip: command not found

The weird thing - my internal IP actually shows up. How do I go about this without getting an error? It shouldn't matter, but I'm using the latest version of Ubuntu.