Sponsored Content
Top Forums UNIX for Beginners Questions & Answers iptables : How to apply masquerade while pinging from DUT to outside network Post 303034785 by slathigara on Monday 6th of May 2019 06:52:25 AM
Old 05-06-2019
iptables : How to apply masquerade while pinging from DUT to outside network

My Device is connected to eth1 interface of the host and eth0 is connected to network.
Now when I am pinging google.com from device after executing below commands on host
Code:
sudo iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE 
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

I am seeing in wireshark at eth0, that during ping request source ip changes from DUT ip to host ip (i.e eth0 ip)
but that does not happen while ping reply , destination IP remains host IP only.
Why does it not show DUT ip as destination IP , Technically my final destination is DUT

For example:
Code:
host IP is x.x.x.x
DUT ip is y.y.y.y
pinging from x.x.x.x

on wireshark:
Code:
ping request  x.x.x.x to google.com -----> this I understood that it is due to masquerading and NAT
ping reply google.com to y.y.y.y expected but I see google.com to x.x.x.x   -----> why no Masquerading here?

 

9 More Discussions You Might Find Interesting

1. IP Networking

Ftp'ing thru a Iptables NAT Masquerade

Greetings to all. My new firewall is giving me one hell of a problem. I'm running iptables and masquerading my intranet thru NAT. But here is the problem. Whenever I try to FTP to a server outside of my lan I get a 500 illegal port error. I've come to the conclusion that NAT is... (2 Replies)
Discussion started by: phrater
2 Replies

2. IP Networking

iptables: log connection after SNAT/MASQUERADE command

Hello! I have the following problem with iptables in Debian 6: My server works as a router and it needs to log server external IP+port for all outgoing connections. But after command SNAT or MASQUERADE traffic is "lost". I mean no following rules can catch those traffic. Everything looks... (0 Replies)
Discussion started by: unlimited
0 Replies

3. UNIX for Dummies Questions & Answers

Sendmail masquerade

Hi, Please tell me what is sendmail masquarade and what is the use of it? Its pretty confusing :eek:.. Is it all about like when mail is sent from sender to receiver, the receiver cannot see the hostname/internal username of sender.. And I found they constitute various classes like class... (0 Replies)
Discussion started by: Priya Amaresh
0 Replies

4. AIX

Sendmail masquerade

I'm trying to configure sendmail masquerading and it seems like I'm having a problem with m4. My main problem is that internally generated emails are showing up externally as originating from: internal_user@internal1.mydomain.com. internal1.mydomain.com doesn't resolve publicly, nor should it.... (1 Reply)
Discussion started by: aix_user1
1 Replies

5. Red Hat

iptables Rules for my network

Hi Champs i am new in Iptables and trying to write rules for my Samba server.I took some help from internet, created one script and run from rc.local : #Allow loopback iptables -I INPUT -i lo -j ACCEPT # Accept packets from Trusted network iptables -A INPUT -s my-network/subnet -j... (0 Replies)
Discussion started by: Vaibhav.T
0 Replies

6. UNIX for Advanced & Expert Users

Https connection to UNIX DUT failing

HI !! I have this setup where I have Windows machine and a UNIX based DUT . I try to make a https connection from my Win to the DUT giving its IP. But,it is not working (It should do). What do u think the problem is ?? I checked the logs , they flag some writesocket:broken pipe error in... (1 Reply)
Discussion started by: leghorn
1 Replies

7. IP Networking

iptables nat/masquerade - how to act as a basic firewall?

edit: SOLVED - see below for solution Hi there, I've inherited a gob of Linux hosts and so am learning linux from the bottom of the deep end of the pool (gotta say I'm warming up to Linux though - it's not half bad) Right now iptables is confusing me and I could use some pointers as to how... (0 Replies)
Discussion started by: Smiling Dragon
0 Replies

8. UNIX for Dummies Questions & Answers

Nullmailer masquerade domain

I am using nullmailer on Ubuntu Linux to relay mails however when I send email or through cron it appear as root@myhostname.domain.com instead of root@domain.com How do I configure nullmailer so the email send appear as from root@domain.com? (0 Replies)
Discussion started by: hassan1
0 Replies

9. UNIX for Dummies Questions & Answers

iptables conditional masquerade

Hi everyone, I have a LAN with : 1 internet box (192.168.1.1) 1 Debian host (192.168.1.224) 3 Windows hosts (192.168.1.32/33/34) The internet box is set to route all incoming traffic to the Debian host (DMZ). Then the Debian host is set to accept certain packets and forward others... (0 Replies)
Discussion started by: chebarbudo
0 Replies
RDS-PING(1)						    BSD General Commands Manual 					       RDS-PING(1)

NAME
rds-ping -- test reachability of remote node over RDS SYNOPSIS
rds-ping [-c count] [-i interval] [-I local_addr] remote_addr DESCRIPTION
rds-ping is used to test whether a remote node is reachable over RDS. Its interface is designed to operate pretty much the standard ping(8) utility, even though the way it works is pretty different. rds-ping opens several RDS sockets and sends packets to port 0 on the indicated host. This is a special port number to which no socket is bound; instead, the kernel processes incoming packets and responds to them. OPTIONS
The following options are available for use on the command line: -c count Causes rds-ping to exit after sending (and receiving) the specified number of packets. -I address By default, rds-ping will pick the local source address for the RDS socket based on routing information for the destination address (i.e. if packets to the given destination would be routed through interface ib0, then it will use the IP address of ib0 as source address). Using the -I option, you can override this choice. -i timeout By default, rds-ping will wait for one second between sending packets. Use this option to specified a different interval. The timeout value is given in seconds, and can be a floating point number. Optionally, append msec or usec to specify a timeout in milliseconds or microseconds, respectively. Specifying a timeout considerably smaller than the packet round-trip time will produce unexpected results. AUTHORS
rds-ping was written by Olaf Kirch <olaf.kirch@oracle.com>. SEE ALSO
rds(7), rds-info(1), rds-stress(1). BSD
Apr 22, 2008 BSD
All times are GMT -4. The time now is 03:24 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy