Questions tagged [nat]
For questions about Network Address Translation (NAT), a method of modifying network address information in IPv4 packet headers.
655
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Sharing messages between 2 peers behind their respective ISPs [closed]
I am new to network programming, so sorry in advance for the lack of know-how.
I want to use curl (just my use case) to send message between 2 peers behind their respective ISPs.
Is it possible to ...
- 101
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10
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Why is NAT rule interfering with private IP RDP connectivity in my Azure network? [migrated]
Firstly I'm not an Azure networking expert...
I am attempting to configure an Azure Virtual Machine within a Azure Virtual Network which has NAT rules applied to outgoing traffic over a s2s-vpn ...
- 101
0
votes
1
answer
56
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Fortigate IPsec site-to-site routing issue
Site A needs IPsec with site B.
Site A networks 192.168.20.0/24 and 192.168.50.0/24 need to reach Site B network 192.168.1.0/24. And the other way around as well.
The problem is that Site A has a ...
- 3
0
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1
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41
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How to combie port forwarding and PAT on Cisco router?
I have a problem, that I cannot bring together working PAT and Port forwarding on a Cisco router.
Here is my topology:
Explanation to topology:
Start connection sourced by 192.168.1.1 with ...
- 1
0
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0
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37
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Cisco IOS XE NAT port-forwarding wtih multiple ports
I am looking for the best approach to organize NAT port-forwarding. The setup is simple: router with one global IP and a local network behind it. Sometimes I need to pass multiple ports into office ...
- 203
-1
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1
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29
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Router SNATs incoming connections [closed]
For some reason, my router changes the source IP of incoming connections.
I can't find which setting makes this happen or if this expected behavior.
For example, this connection was initiated by an ...
- 99
0
votes
1
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63
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Should a router behind the internet gateway run source NATing or masquerading if the gateway router is masquerading?
Edit:
On a multi-router network, should a router (R2) behind the internet gateway (R1) run source NATing or masquerading if the gateway router is masquerading?
At this time I can ssh from a host on ...
0
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1
answer
37
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Router cannot access LAN with public IP [duplicate]
I have the following setup:
ISP
|
|
external interface (public ip)
/
Router (running OPNsense)
\
internal interface 192.168.0.1
...
- 1
1
vote
1
answer
55
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Nested Network with same IP Space
I have a router (Teltonika RUT) that is connected via its WAN port to a network (let's call it "Big").
The IP Space of the "Big" Network is 192.168.1.0/24 with the Gateway on 192....
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1
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119
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Why does EKS Fargate require NAT?
EKS Fargate is an AWS service for "serverless" hosting of some pods in a Kubernetes cluster. The docs mention that NAT is obligatory, why is this?
I tried using traceroute from a Fargate pod....
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1
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518
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How localhost and its opposite 0.0.0.0 works
Here I am running an application on a computer, host=localhost, the application runs on localhost:5000, or 127.0.0.1:5000.
When the computer accesses 127.0.0.0/8, or 127.0.0.0 subnet mask 255.0.0.0, ...
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3
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2
answers
147
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Is NAT66 really not used when there are all these apps exposed by public load balancers?
I am imagining a Kubernetes IPv6 based cluster with Nodes in a private subnet and an Ingress deployed that sets up an application load balancer in a public subnet which receives a public IPv6. You can ...
- 41
1
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0
answers
20
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Firewall not reverse translating NAT address in VyOS GNS3
I'm using two VyOS images as Firewalls in gns3, to which I have connected two routers, one from an inside network and another from an outside network. I configured NAT in both for the internal ...
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13
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Where is 1.1.1.1 really located? [duplicate]
I'm courious how this works:
When ping-ing 1.1.1.1 I get results of roundabout 15 ms, where 1.1.1.1 is located in California, according to iplocation.net.
When ping-ing a random ISP from California I ...
0
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1
answer
48
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Hosts behind PAT not able to communicate with each other
Suppose I have the following network layout, with two routers connected directly, with Port Address Translation (PAT) setup on both of them. The first router labelled Router PAT 1 have been configured ...
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2
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322
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Problem with Configuring Selective DNAT for HTTP Traffic on Fortigate Firewall
I'm currently in the process of setting up a new Fortigate Firewall and have run into an issue while configuring DNAT. From what I understand, this is done through Virtual IPs in Fortigate. My goal is ...
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1
answer
52
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conntrack expectation on directed broadcast [closed]
I'm testing out a setup that I would reproduce in a production environment if I get it work. What I have:
A wireless network 192.168.88.0/24
An IoT device X in the wireless network
A Teltonika router ...
- 3
0
votes
2
answers
148
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How to connect TCP server behind NAT
I need to establish TCP connection with a server located behind the NAT. The simple solution is to reverse the connection and ask the server to connect to the client, but then I am unable to use ...
0
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0
answers
125
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Clarification of external interface vs source interface filter in Fortigate DNAT/VIP
On a Fortigate firewall, one can configure Destination NAT using the DNAT & Virtual IPs section of the GUI, or the config firewall vip section of the CLI.
When you create a DNAT object using ...
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1
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126
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Problems with twice-NAT on Cisco 3548
I'm trying to get Twice-NAT working on a Cisco 3548 switch. I have a VRF set up with 2 L3 ports on it -
Eth1/33 has ip address 20.20.255.250/16 and is nat inside
Eth1/34 has ip address 10.10.1.211/24 ...
- 101
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1
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368
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How to remote access CCTV's device behind CGNAT for IPv4, and device doesn't have support for DDNS IPv6? [closed]
TL;DR
Multiple locations with local CCTV. How to remote access all of them, with an ISP that services IPv4 behind CGNAT and the DVR doesn't supports DDNS for IPv6. DVR also offers API, SDK, P2P and ...
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1
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85
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Why can't we use large-scale NAT system with thousands of private IP addresses assigned to a single public IP
Instead of assigning everyone an individual public IP address, could we use a very strong NAT system with thousands of private IPs behind a single public IP? This could reduce public IP demand and ...
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2
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354
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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 ...
- 15
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votes
1
answer
51
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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 ...
- 1
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votes
2
answers
124
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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 ...
1
vote
1
answer
711
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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
answer
45
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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, ...
1
vote
1
answer
269
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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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0
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194
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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 ...
- 111
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1
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95
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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 ...
- 103
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1
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96
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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
answers
525
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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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1
answer
44
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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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637
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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
answers
34
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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 ...
2
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1
answer
1k
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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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107
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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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1
answer
42
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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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5
answers
106
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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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483
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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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631
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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 ...
- 121
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2
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2k
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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 ...
0
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1
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98
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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 ...
- 305
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2
answers
175
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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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2
answers
87
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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 ...
- 111
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2
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190
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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 ...
- 103
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votes
4
answers
2k
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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 ...
- 41
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1
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426
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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 ...
- 877
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votes
2
answers
90
views
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 ...
- 877