Questions tagged [nat]
For questions about Network Address Translation (NAT), a method of modifying network address information in IPv4 packet headers.
633
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How to apply a Route-Map to a NAT connection
I am following a tutorial about route-maps on youtube. https://www.youtube.com/watch?v=2YlsXcT1Pjw
There is this topology.
The default route on R1 points to 10.10.10.2
In the video he just shows how ...
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1
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2 Routers for PPPoE and NAT 5 Public IP [closed]
My ISP have provided me with 5 Public IPs. I tried to NAT these 5 IPs to our local server by using this setup. The primary router will be setup for the internet connection while the one-to-one NAT of ...
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Communicating to a device with a random IP, Subnet Mask and Gateway
I think am looking for a way to reliably communicate with devices connected to the network with "wrong" configurations.
Our company sells products that can have their network settings ...
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1
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170
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How to use 5 static ip addresses with virgin media broad band
I have installed virgin media business broadband and the package comes with 5 static ips. These IP are GRE tunnels from the HITRON router to virgin.
the IP addresses are for example
66.66.66.65 - 66....
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1
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Simple question about NAT [duplicate]
So I am learning about NAT. I understand that it changes IP from public>private and vice versa. From my understanding, when a packet or info gets sent to the public ip towards the private ip, ...
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1
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Communication between hosts on different local networks
I understand how NAT works in case of communication between one, local host and a server with specific public IP address. The host is sending a request, it pushes the packet with destination IP ...
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How to forward UDP unicast messages to multiple destinations [closed]
I am trying to forward a UDP Unicast message so that it cant be received by multiple computers. Can anyone point me in the right direction for how to accomplish this?
Here are the details:
There are ...
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Is internal network traffic sent to private subnets via their NAT Server?
Similar to this question, I'm wondering how resources in my public subnets communicate with those in my private subnets - when there is a NAT service present.
My impression is that a self-managed NAT ...
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NAT configuration behind pppoe with virtual server
my CISCO 3925 router is handling pppoe, NAT, and DHCP server..
My local LAN is 192.168.1.x and it's behind that NAT.
I'm trying to enable access to a DNS server that's on this LAN (192.168.1.191 tcp/...
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3
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Can I use the network and broadcast IP addresses of a /24 subnet, when the /24 subnet is included in a larger /22 subnet range for NAT?
I'm wondering if I can use the network and broadcast IP addresses of a /24 subnet, when the /24 subnet is included in a larger /22 subnet range for NAT?
PS: Please consider that 198.51.0.0/22 is ...
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Connect site-to-site private networks [closed]
I used VPN to connect site-to-site private networks from A to B. It worked fine. Then I used NAT for (1) hiding private networks and (2) LAN of 2 sites could access the Internet. The problem is that ...
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Pfsense NAT with site-to-site VPN
For a client I am building a network solution that enables them expanding their available online presence.
I am running into a problem with port forwarding to an IP which is routed over an OpenVPN L3 ...
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0
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How to allow cisco to log on to a specific ip port using nat
Good afternoon, I use Cisco 7201
I create a network on the gi0/0 interface connecting to a dhcp provider and get a static ip address, also on the gi0/1 interface I create a network where my 5 servers ...
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1
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219
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Does UDP work with NAT
I'm learning the TCP and UDP protocols and I have a question about UDP.
I used C to develop a UDP server and a UDP client in my LAN and it works as expected. The server and the client could ...
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2
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Hide private IP address
DS has 7 VLANs and 7 DHCP pools respectively. There are 3 trunk links to 3 access layer switchs to share VLANs. Its VLAN interfaces and DHCP pools:
ip dhcp pool vlan10
network 192.168.10.0 255.255....
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ACLs block connection
Here is my configuration on ISP router:
interface GigabitEthernet0/0/0
no ip address
duplex auto
speed auto
!
interface GigabitEthernet0/0/0.10
encapsulation dot1Q 10
ip address 192.168.10.1 255....
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Are there any methods of differentiate between a single computer and a NAT router?
As far as I know, a traffic from a NAT router should appear similar to traffic from one computer with a single IP address. If you do not have any access to a network (let's say you are an ISP), can ...
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2
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If there's a NAT-capable gateway between WAN and a switch, why is a switch helpful?
To preface this question, my question is somewhat related to what I'm trying to understand as the difference between layer 3 switches and routers. The main difference between the two is that layer 3 ...
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If your ISP already has a gateway, why do you need another gateway with NAT to come before a layer 3 switch?
Please bear in mind that I am learning and have never set up a network with routers and switches myself. Also please bear this is sort of going to be loaded question because there are multiple layers ...
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connect two private network using pfsense
I have two pfenses (say p1 and p2) in two separate networks. Each has a public IP. There is an internal network on each side (say n1 and n2). I want to connect these two networks through these two ...
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Can somebody help me understand this static NAT example
I have the following example:
From my understanding of static NAT the client makes a request on the inside global address of a resource, in this case the webserver. (http://209.165.201.5). The request ...
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in Twice NAT, why cant external network be advertised to private network?
This is from the NAT RCF:
The following is a description of the properties of realms supported
by Twice-NAT. Network address of hosts in external network are unique
in external networks, but not ...
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Best way to configure for port forwarding
I am using a Peplink Balance 30 router. Right now I have only one public IP. I have set up the LAN for 192.168.8.1. I have five devices on the LAN side, including two Ubiquiti Rockets and three IP ...
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IPTables how to nat 10.8.a.b to 10.0.a.b? [closed]
The problem -- Translate 10.8.a.b to 10.0.a.b ?
I have a VPN setup to a bastion host. I'm attempting to map 10.8.0.0/17 into 10.0.0.0/17 so that the IP address 10.8.1.1 gets mapped to 10.0.1.1 in my ...
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Public IP Configuration which has a private gateway
I bought a public IP from my ISP and they provided me with the following details.
WAN IP :10.129.69.157
LAN IP : 196.188.173.32/30
How do I configure this on my side ?
The told me to do configure as ...
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Do I get any security benefits by NATing a network that's already behind a firewall?
I'm deploying a new network for IOT devices, this new network will be behind a firewall. I've been suggested to also get the network natted to further improve security. Does this really add any ...
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Why is it necessary to configure an ACL when configuring Dynamic Nat?
When configuring Dynamic NAT, why is it necessary for us to also create and specify an access list which dictates what kind of traffic should be translated?
Couldn't we simply skip this step, so that ...
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Could we use an IP address in our network that does not fall into the RFC 1918 range?
RFC 1918 specifies 3 ranges of IP addresses as private
10.0.0.0/8
172.16.0.0/12
192.168.0.0/16
So in a real network, only these IP addresses could be used? What if I assigned a host on the network an ...
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How to NAT a unicast address to a broadcast address?
I have a 800-Series router connected in the following configuration:
Port GigabitEthernet7 is connected to an external server (192.0.2.251) that sends unicast UDP to destinations 192.0.2.42:45100 and ...
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378
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Cisco ASA not accepting external traffic without NAT configuration
First of all, I am quite newie in the cisco world, so this could be some easy stuff that I'm missing.
My first problem is trying to understand why a Cisco ASA5585 does not show traffic while doing a ...
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When a new entry in the NAT table is created and an entry in the NAT table is removed?
When using TCP, is a new entry in the NAT table created when a connection is made? and is an entry in the NAT table removed when a connection is closed?
If I am correct, what happens if both ...
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How can a port be both be used to identify a private IP, and also to connect to a specific service?
Sorry if im asking something nonsensical, im still trying to wrap my head around these terms.
Heres my understanding
NAT is the process of translating a private IP to a public IP, lets make an exaple ...
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Site-to-Site VPN with BOTH sites behind NAT (mobile data routers)
I have 2 sites (call them "A" and "B") which connect to the Internet using 4G mobile data routers - don't knock them, I'm getting 200Mbps downlink and 30Mbps uplink, faster than a ...
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Do NAT Gateways Need to be the First Address of the Network?
NAT gateways are often given the first usable address in an address space.
Do any protocol specs require this? Or is this just a convention?
I skimmed RFC 1918 and RFC 2663 but didn't see anything ...
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How does NATing work
I'm not 100% understanding how NATing works. Let me setup our network and talk this through.
So first of all, lets say that I have an IP size of 4 bits so 16 possible combination. The only private ...
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Full Cone NAT on Cisco router in Packet Tracer
I am trying to create a network with two subnetworks with private IPs. I need to configure symmetric NAT on edge routers within the subnetwork.
Diagram:
I need to configure NAT on Router0 and Router2....
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Is it possible to send network messages with "Fake" Local Network(192.168.x.x) destination IP but actually reaches the destination via internet?
I am configuring a MySQL server that is only intended for computers from internal network/local network machines to access.
Now MySQL has a "bind IP address" setting that, if I set it to the ...
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546
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Cisco ASA VPN tunnel shows up (phase 1 and 2, MM_ACTIVE), but no traffic passes
My end of the tunnel is on an ASAv in AWS. (version 9.14)
show crypto isakmp sa
4 IKE Peer: 212.239.x.y
Type : L2L Role : responder
Rekey : no State : ...
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How are we still able to use IPv4 address even with NAT? [duplicate]
My question is why haven't we run out of IPv4 public IP as well because now almost all home has a router which is assigned a public IP. Is it possible to have multiple layers of NAT on the router-ISP ...
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Why are External NAT ports different when both NATs are restricted cone? [duplicate]
I'm in the progress of implementing my own Signaling server with UDP hole punching, everything have been smooth up until both hosts were behind Restricted Cone NAT, then the ports for P2P ...
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813
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Checkpoint Firewall using wrong Source IP when establishing a VPN
I have a checkpoint VSX environment running r81 and I have a DMZ firewall that has two external interfaces. One that goes to the Internet and one that goes to a 10.0.0.0/8 network that connects to ...
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why ip adresses are divided into network portion and host portion when we already have NAT [duplicate]
I don't understand why ip adresses are divided into network portion and host portion? is the host portion really necessary when we already have NAT?
for example, if ip addresses only have network ...
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Trying To connect Router4 to internet
In the picture, I have a part of my topology. The concept is that I am trying to configure OSPF in my network. Internet is a nat cloud module. The routers are all iosv routers.
ISP 1 has the following ...
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Configure NAT in Vyos Router
I have the following diagram, and I want that R2 and each client connected with R2 have access to the internet. For that I configured NAT in R1 with the following commands:
#set nat source rule 10 ...
user80646
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How NAT router use layer4 contents in layer3?
I followed from this question and @PeterGreen's Answer , and come to know that NAT router working in layer3, but using layer4 contents(layer4 port number,layer4 checksum). My question is when layer3 ...
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Does Port Forwarding limit ports available to NAPT?
I'm wondering if routers limit the possible ports available to NAPT when port forwarding is configured. For example, given one public IP address all but two ports assigned via port forwarding, would ...
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Switching Internet connection on Cisco ASA
I use Cisco ASA in branches of our organization. Each device has an IPsec tunnel that connects to the main office. To access the global network each device also has a NAT. Recently, a task arose to ...
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818
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What is the use of SNAT (Static Network Address Translation)?
If SNAT is used to map internal private IP addresses directly to a non-changing public IP address, why not simply assign the public IP addresses directly to each host itself? What advantage dose SNAT ...
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963
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Why or when do we need Layer 2 NAT? [closed]
What is the point of public addresses in Layer 2? Why or when do we need it? When is it healthy to use? Or is it even a common thing?
Sorry I am kinda new at networking and I just googled it but ...
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2
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How can I use scapy to make a port appear open-device behind NAT?
This has been asked in stack overflow like 7 years back. I don't see the correct answer there. Is there any way to do this?
While this packet keeps on being transmitting, doesn't the other end see the ...
