Questions tagged [nat]
For questions about Network Address Translation (NAT), a method of modifying network address information in IPv4 packet headers.
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Sophos XG Virtual Host Load Balancing
I own a Sophos XG cluster (v18) and I need to balance http/https
traffic at lvl 7, by virtual host, among different servers.
To be clear: I need to balance the vhost www.example1.com between 2 servers ...
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32
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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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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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Is Port Forwarding a type of NAT? [duplicate]
I am reading about Port Forwarding and NAT, these two concepts seem similar to me.
Is Port Forwarding a type of NAT?
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49
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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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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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147
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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 ...
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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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Source Port NAT with VPN [duplicate]
I understand that a router (like an home router) does source port NAT (as the public IP for a LAN is normally one). If I run a VPN Client (like Open VPN) on a computer in the LAN and if the VPN packet ...
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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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Error cluster with packets balacing through NAT
Im trying to make a web cluster (HTTP and FTP) with 3 linux machines where the packets are balanced through NAT and im using Bridge interfaces and HSRP, because im using 2 routers(using c3660 image) ...
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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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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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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 ...
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NAT in ASA (5505) Firewall is not working for VLANs configured in Layer3 Switch?
Toplogy:
Tool Used: Cisco Packet Tracer
Scenario:
NAT for hosts in any of the VLANs of Layer3-Switch not working.
Ping requests reaches outside server, but NAT is not working so ISP
Router can't ...
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How to configure NAT in Cisco ASA Firewall for all VLANs connected to layer 3 switch? [closed]
Topology:
How to set up NAT in Cisco ASA Firewall (in Packet Tracer), when there are VLANs in the network?
In the current approach, NAT is not working to reach the server (8.8.8.8) from any of the ...
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Cisco 2851 Static NAT Entry - Similar Static Entry Already Exists
Thank you in advance.
I have a few 2851 Cisco ISR. This is my NAT Pool config;
ip nat pool NAT-Pool 38.xxx.xxx.193 38.xxx.xxx.206 prefix-length 28
ip nat inside source list 1 pool NAT-Pool overload
...
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What's the procedure to limit a subnet on a Cisco router from seeing another subnet when both are using NAT?
I have a Cisco 891F router. The internet is hooked up to G8. The student network is Vlan 200, and the Office is Vlan 100.
(I know the internet has an internal subnet (192.168.1.5), but that's because ...
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NAT not working in cisco packet tracer
Cisco Router Version: 16.7(3r)
Cisco Packet Tracer:8.0 x64
Router(config)#interface dialer 1
Router(config-if)#ip nat?
% Unrecognized command
Router(config-if)#ip nat ?
% Unrecognized command
Router(...
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Linux: address the same IP range (different networks) via two interfaces masqueraded [closed]
Not sure whether it can be done:
Due to a legacy setup there are two separate networks that both use the same class C subnet 192.168.0.0/24. I have a Linux box with two physical interfaces wherein ...
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Are NAT external:internal mapping types the same for UDP and TCP
Suppose I use a STUN server (UDP) to determine that a client's NAT randomly assigns external port values.
Does this imply that the client's NAT will also assign random external port values when using ...
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How to perform an inbound and outbound NAT at the same time in Pfsense?
I have a rule on a stormshield performing NAT on both the source and the destination address. It is done very simply in one rule. Example :
--Before translation-- --After ...
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3
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Private IP address vs Local IP address
Say a router is connected to two devices. Now the router will give those two devices different private IP addresses. The router itself has a private IP address (which serves as the default gateway for ...
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Questions about NAT
So i just started learning about NAT and networking in general. As powerful as this technology may seem, it was specifically made for reducing the amount of IPV4 addresses used throughout the internet,...
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Cisco ASA nat from inside to outside, but network that is routed to inside interface
So is it possible to nat from inside to outside interface but not the inside ip subnet, rather the ip subnet that is routed to inside interface?
#object network remote_ip_subnet
#subnet 192.168.1.0 ...
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How does NAT modify the headers correctly?
How does the process of replacing the incoming message (say from stackexchange) to the router, and modifying the header with my PC IP happen? How does the router know which IP to insert there? Is ...
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CGNAT port allocation
I'm planning to implement CGNAT in service provider with a10 networks.
So, the question is how many private IP addresses I can NAT through one public IP ?
One public IP = 64511 ports = 400 ports per ...
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Multiple VLANs with PAT
I'd like to know if it's acceptable/possible to use PAT with multiple VLANs, by using the same translated IP address for all VLANs.
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Is this a good network configuration?
I am trying to configure ip sla for non directed link . I have configured static route to reach to non directed link
1 configured track
2 configured ip sla
3 configured access-list
4 configured NAT
5 ...
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2
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Palo Alto Firewall: Why is double NAT needed?
The diagram shows my current network configuration. (Where X is 10).
I have the firewall interface E1/2 at the left configured to 192.168.10.1/24. It is in a trusted security zone. A DHCP server is ...
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Configure port forwarding with interface command within VRF
We are working with VRFs and having a look into the NVI NAT configuration. Without VRFs, we can configure following:
ip nat source static tcp 10.0.0.2 80 interface Dialer1 80
ip nat source static tcp ...
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NAT Unable to Translate on Packet Return
I am currently working with the network above. When ever I send a packet across from a network, on the return to the router it is unable to translate back and ends up dropping the packet. I am how ...
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Why Does Symmetric NAT imply a TURN Server? [duplicate]
I am using ICE/STUN in the context of WEBRTC.
I understand why STUN does not work with symmetric NAT.
The answer to that question is here:
why STUN doesn't work with symmetric NAT?
I am asking a ...
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Allow only specified set of IPs to use external port on pfSense
I have a pfsense router and a NAT rule that allows a port redirect.
| GitHub | - ( Internet ) - [pfsense] -net port translation- [ Jenkins ]
I want gitHub to be able to reach my jenkins, but no other ...
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Why do we need private IP address range?
When it comes to local networks, you have the freedom to use any IP address you want for your network since it doesn't need to communicate on the internet with other devices. However, the RFC ...
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Help understanding NAT/PAT - With example
Would anyone be able to clarify what ive been thinking is correct or if this is a complete misunderstanding and possibly answer these questions if you have time?
So I understand that NAT/PAT is giving ...
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Concurrent site-to-site VPN tunnels through dual ISPs (with 2 couples of Cisco ASA) between same devices
I currently have a simple site-to-site VPN setup, connecting machines from site 1 to site 2 through 1 ISP, using a set of ASA 5506X. All is good.
I'd like to "double" that setup for ...
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3
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PIM Packet and NAT
Is it possible to NAT PIM Join packet?
Assume the receiver and the source are in two different networks (address regimes). Thus NAT is required. The upstream source and the groupe are included in the ...
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