NAT Packets/Port Openine

Thread Tools Search this Thread
Special Forums IP Networking NAT Packets/Port Openine
# 1  
Old 08-19-2002
NAT Packets/Port Openine

Firstly, I have no knowledge of hubs, so please keep any advice simple!

I have a UNIX hub, connecting three PCs and would like to know if the hub has NAT translation for incoming packets and if th hub is able to NAT translate packets coming in to a local (internal) LAN address..
# 2  
Old 08-20-2002
Do you mean that your Unix host has 3 LAN connections (interfaces) and acts as a hub ?? If yes, then NAT is available between the interfaces so long as each is defined with a different subnet address. Best Linux example is the use of 'ipchains' for configuring simple NATing rules (IP Masquerade) and configuring your host to act as a router between the subnets. See

If you have a seperate piece of network equipment, i.e. a hub, then I would suspect that the answer is no. You will need to purchase a piece of equipment with NAT capability, i.e. a router.

# 3  
Old 08-20-2002
wait i have a question, if you set up a unix box running a firewall and routing, the box has two network interfaces, one is connected to a dsl modem and the other to a 4 port switch, that computer cant do NAT?
# 4  
Old 08-21-2002
True you do not have to run NAT if you are allowing the equipment your communicating with at the end of the dsl link to communicate via the assigned IP addresses of your devices on the 4 port switch. This is not a very secure firewall practice, but is completed by definition of routing (IP forwarding etc)!?
However assuming that you are now talking about an internet connection and unless all of the devices connected to the 4 port switch have a registered IP address, NAT must exist to allow the internal devices IP addresses to be translated to an address recognised (registered) on the internet. This translation may well be performed on your dsl modem (functionality of device dependant). By basic definition of a firewall, NAT is used to mask internal addresses.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Solaris

How to find port number wwn of particular port on dual port HBA,?

please find the below o/p for your reference bash-3.00# fcinfo hba-port HBA Port WWN: 21000024ff295a34 OS Device Name: /dev/cfg/c2 Manufacturer: QLogic Corp. Model: 375-3356-02 Firmware Version: 05.03.02 FCode/BIOS Version: BIOS: 2.02; fcode: 2.01;... (3 Replies)
Discussion started by: sb200
3 Replies

2. Infrastructure Monitoring

Snmp and NAT

Hello, I am facing this scenario: three or more remote LAN (peripheral offices), with the same devices (printers, NAS) in each of them. Those LANs have the same network addresses, i.e.192.168.1.* (are connected to WAN via NAT). I need to collect snmp traps from a central server (public IP).... (4 Replies)
Discussion started by: neutrino
4 Replies

3. Debian

Iptables Nat forward port 29070

Hello, the Nat and the forward worked on my debian server up to the reboot of machines. The following rules*: /sbin/iptables -t nat -A PREROUTING -p tcp -i eth2 -d --dport 29070 -j DNAT --to-destination /sbin/iptables -A FORWARD -p tcp -i eth2 -o eth0 -d... (0 Replies)
Discussion started by: titoms
0 Replies

4. UNIX for Advanced & Expert Users

ipf/ipnat NAT/port forward issues

I've been going crazy trying to get this working. Here's the situation: we have a Solaris 10 box that connects an internal network to an external network. We're using ipf/ipnat on it. We've added a couple of new boxes to the internal network (, .101) and want to be able to get to port... (1 Reply)
Discussion started by: spakov
1 Replies

5. UNIX for Advanced & Expert Users

copy packets from one port to another by iptables

I would like to copy data flow (not redirect!!!) from 1567 port to another 1194 port on same computer. The 1567 Port already binded by Scream program (it is bisy). Is it possible to do it by iptables or for it nesessary another programs? Can you help me in the decision of this question? (1 Reply)
Discussion started by: yanat
1 Replies

6. IP Networking

Retrieve exchanged packets on a particular port

Hi, I want to find out someway to get the number of exchanged packets (received, transmitted or both) on a particular service (so per Port). There are many network tools on linux (netstat, /proc/net/dev, iptables...) but I can not find an efficient way to get these information. All I can do is... (3 Replies)
Discussion started by: nightoy
3 Replies

7. IP Networking

Help with capturing/reading total packets on specific port number

Hi guys, I'm using a Linux system(Ubuntu) and I've been trying to find a method to read the total packets received/sent on a specific port (e.g port 80 or port 25) on a local machine. I can read the overall total packets received/sent from the /proc/net/dev file system. But what I can't do is... (2 Replies)
Discussion started by: lildee
2 Replies

8. IP Networking

L2 nat

Hi All, Is there any possibility to change the IP address of a package according to its MAC address. It would be a sort of L2 NAT. (i.e. If the MAC address is 00:1A:A0:1E:XX:XX so the dir IP will be 192.168.X.X) Thanks!. (4 Replies)
Discussion started by: lagigliaivan
4 Replies

9. IP Networking

NAT address

Hi Could anybody tell me the solaris command to display the NAT address Thanks in advance (5 Replies)
Discussion started by: axes
5 Replies

10. BSD

proxy or NAT

how do i configure proxy in freeBSD or NAT so that when i set it up as a server can connect other to my new gateway (0 Replies)
Discussion started by: AkinOkin
0 Replies
Login or Register to Ask a Question