Questions tagged [nat]
For questions about Network Address Translation (NAT), a method of modifying network address information in IPv4 packet headers.
1
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0answers
22 views
Juniper SRX Destination NAT for L2TP server
I have a L2TP server on my LAN which I would like to access from WAN and there is a Juniper SRX standing between these two networks.
I've had some success with this post:
https://forums.juniper.net/t5/...
0
votes
0answers
17 views
NAT->Multicast Setup->ACL? [duplicate]
I am a network newbie and would be amazing for some help.
I trying to input multicast (239.10.1.11) onto a router 0/0 interface and would like to output multicast on (239.0.0.2) on interface 0/1. The ...
1
vote
2answers
30 views
Can a host in a public network communicate with a host in a private network, by layer 3 alone?
Suppose a private network and a public network are connected by a router or some other device.
After a host in the private network sends a message (e.g. a HTTP request) to a host in the public ...
0
votes
1answer
32 views
What are the differences between packet forwarding and network address translation in layer 3?
What are the differences between packet forwarding and network address translation in layer 3?
Is packet forwarding done by a router between two networks that use
public IP addresses?
Is network ...
0
votes
0answers
14 views
how do vpn apps work in order to bridge out of private telecom network to the internet [on hold]
Because recently there has been a trend in my country whereby people with telecom hosted sim-card android phones had vpn apps that allowed them to access internet without billing (i.e. without top-up-...
1
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2answers
39 views
Unable to access Server over VPN behind 2 Fortigate Firewalls; however ping is working
Client -> VPN -> FG1 -> FG2 -> Server
Created a VPN tunnel with remote IP 10.20.30.4/32 and local ip 10.20.30.40/32
on FG1, NAT/VIP is established with VIP as 10.20.30.40 and server IP as 192.168.2.6
...
2
votes
2answers
40 views
Are both VPN and NAT alternative ways to provide access to a private network?
https://en.wikipedia.org/wiki/Virtual_private_network
A virtual private network (VPN) extends a private network across a public network, and enables users to send and receive data across shared or ...
-2
votes
1answer
42 views
How do i find out if a LAN is behind a multi-level NAT? [closed]
Not much i can specify here - its obvious that my CPE is NATing my LAN, but how do i find out if my ISP is using a carrier-grade NAT (obviously, without asking them)?
I heard that port forwarding is ...
-1
votes
1answer
37 views
MAc address or IP address? which one gets used from my pc to router? [duplicate]
Question 1) which one is used nowadays? NAT or PAT?
Question 2) as I knew, when my pc requests some website, what happens is , the data(packets) from my pc go to router. then router makes the request ...
2
votes
1answer
30 views
How do I find out which NAT is getting hit?
I can see in packet captures that my packet's destination IP is getting translated. How do I find which NAT statement is responsible for the conversion if my device has over 200 NAT rules? I'm using ...
0
votes
1answer
32 views
How does packet traversal works over a public network with NAT overloading
Let's say I have a private network connected to the internet with default gateway 192.168.1.1 on Router1. Now a host(Host#1, 192.168.1.10) on this network wants to send a packet over the public ...
0
votes
2answers
56 views
How can AWS restrict access by private IP?
The official AWS docs state:
If you are connecting through an ISP or from behind your firewall
without a static IP address, you need to find out the range of IP
addresses used by client ...
0
votes
0answers
14 views
How to connect private networks? [duplicate]
I need to connect two private networks. I have the same IPv4 addresses and need to establish connection between them.
• How can I connect them? (NAT?)
• What type of routing to use? (I know static ...
0
votes
0answers
39 views
Cisco L2TP Tunnel and NAT
I have problems with NAT clients connected to an AP .
This AP has an L2TP tunnel established to a Cisco router (7206VXR).
The session is UP and the router can ping the IP of the client.
The client ...
1
vote
0answers
39 views
Why NAT type detected by `stun` command depends on used STUN server? [closed]
# stun -v stun.counterpath.net |& grep '^MappedAddress\|Primary'
MappedAddress = 93.84.76.218:20458
MappedAddress = 93.84.76.218:20458
Primary: Independent Mapping, Port Dependent Filter, preserves ...
0
votes
0answers
56 views
Flow is Denied by Configured Rule on Cisco asa 5520
Recently I upgraded my firewall hardware from an ASA 5505 to an ASA 5520. Since I am a small startup company on a tight budget, I have purchased a used firewall. Unfortunately, the firewall runs on ...
1
vote
1answer
71 views
Accessing internal website from subnet
I have the following network:
- Edge Lite 3 router with public IP on WAN (eth0) and 2 LANs:
1) eth1 192.168.1.11/24
2) eth2 192.168.2.11/24
eth1 is DHCP, I have several work laptops inside.
eth2 ...
0
votes
1answer
23 views
A question on NAT [closed]
I know ISP's use NAT to provide a home user with a public IP. If multiple devices connect to the internet using the same router all will have different private IP addresses but similar public IP ...
0
votes
1answer
18 views
Daisy chaining IOT devices without switches? [closed]
I have multiple IoT board with two network interface in each device. I want to connect them in a daisy chain without help of switch. The eth1 of first device will be connected to eth0 of second device,...
4
votes
1answer
327 views
Will the data transfer with the destination on the same LAN network be routed through the internet when the WAN IP is used?
I'm planning to set up a Nextcloud locally. I will be using my own domain with a DNS record to connect to my WAN IP and port forward the needed ports to the local machine running Nextcloud.
Now of ...
2
votes
2answers
172 views
NAT Translation Table Port Number
I had a practice question about a NAT-enabled router with outside address 24.34.112.235 and inside network 192.168.1/24 and three inside hosts .1, .2 and .3. The three hosts all open two connections ...
1
vote
4answers
109 views
Can I make 2 ISP providers' IP addresses into 1 IP address?
We have 2 ISP providers (X, Y) and we have connected the ISPs to a core switch>Sophos firewall>Switch rack>end user (LAN & WiFi). This ISP works on fail-over mechanism.
The issue here is that we ...
3
votes
1answer
147 views
PAT not translating at all
I am studying for my CCENT.
I threw together a PAT practice lab.
Other than DHCP and RIP everything is pretty stock.
No VLANs
No security
Just NAT overload on ACCESS router.
I am stumped why it isn'...
4
votes
1answer
53 views
Source NAT on Juniper SRX300
I'm having issues setting up the Source NAT on my SRX300 firewall. The firewall is connected to an LC-panel through a fibre optic cable in port 0/6. I have set the public ip on that interface and have ...
3
votes
2answers
42 views
How could a response be sent to the requestor without requestor's address?
I'm reading this talking about the differences between two fire-and-forget message (for example, under UDP) and a request-response communication (for example, under TCP). I came across this:
The ...
1
vote
1answer
80 views
Access internal webserver with domainname points to external IP
We have a webserver on our LAN.
Externally, we can use the public domainname (let's say business.com) to access the website.
Internally, we need to use the local IP.
We also want to use the public ...
1
vote
1answer
62 views
How to run SIP phones in the LAN (NAT Overloaded to single IP)?
We have a small office network switch connected to a DSL modem for internet and telephony access. Now we would to extend network to another location in the same building for which I deployed a cisco ...
2
votes
1answer
313 views
Can VPN on router connected to the modem bypass a double NAT created by two routers unbridged and connected to each other?
I can't seem to get my head around this scenario. If I am right, a VPN configured on the client-side/workstation would definitely bypass double NAT but on this scenario:
Modem <-bridged-> Router ...
2
votes
0answers
61 views
Cisco - Change both source and destination on NAT [closed]
Note: As usual I'm dealing with single device so there are limits on what I can change outside of this router.
Device: Cisco 1841
IOS: 12.4(13a)
Vlan1 - IP: 192.168.0.3
Vlan1 (Default Gateway): 192....
8
votes
1answer
251 views
NAT VLANs with same IP Subnets
I have a VMware environment in which VMs are running a simulation suite. The software used has hardcoded IP addresses, about 10-15 VMs, and we are running multiple instances of this software each in ...
56
votes
7answers
15k views
Why are IPv4 addresses running out?
I understand that we are running out (or ran out already?) of IPv4 addresses, but I don't really understand why that is. Right now, every home has its own IPv4 address (dynamically assigned, but still,...
0
votes
1answer
40 views
Cisco IOS 12.3 - Mysterious NAT - Where is it defined?
I have the following config (IOS 12.3):
A.B.C.13 stands for the outside, public IP, bound on interface Fa0/1.52
37.247.X.206 is a public client I am using to test
x.x.x.n stands for a random public ...
0
votes
1answer
35 views
Does the VM under the NAT network can contact the dedicated servers? [closed]
I have bellow snapshot's network configration:
in the Dedicated Control Server(172.18.1.249) there is a VMware VM1 with ip 172.18.1.247, and it use the NAT network(gateway is 172.18.1.248).
I want ...
2
votes
1answer
497 views
Port-forwarding rule on Cisco ASA not working - “Drop-reason: (acl-drop) Flow is denied by configured rule”
New to Cisco, so I hope this question isn't too noobish. I am trying to setup a port-forwarding rule to allow "any" SSL traffic in from "Outside" to the web server on my LAN. The problem is apparently ...
1
vote
1answer
125 views
ASDM access broken on Cisco ASA 5505 - NAT rule gone wrong
I was trying to setup NAT and Access Rules and apparently did something very wrong because now I cannot get into ASDM at all. I've tried multiple machines and all of them time out. Also the landing ...
2
votes
1answer
49 views
Network ( routing and switching) , security
In my company network i am installing new cisco2811 router but i have problem, my LAN network can not ping and access network. i get point to point internet from ISP.
PTP IP is 192.186.86.200/24 and ...
2
votes
1answer
60 views
Firewall Rule 'Both Ways'
I'd like to think I have a good understanding of NAT and Firewall rules at a basic level, though please correct me if I'm wrong at any point. I've seen many products list their firewall requirements ...
1
vote
1answer
110 views
Is an SBC sufficient and can it NAT
We have a gateway which faces out to our VoIP SP. As we get more users we need some security in front of it.
Currently our gateway terminates directly to the SP. We would like to put a SBC in front ...
4
votes
6answers
840 views
Why is classful addressing considered waste?
I am trying to understand the addressing strategies. But there is something which I can't grasp. Maybe I am missing a very basic point, if so, I am sorry beforehand.
From my researches, let's say, if ...
1
vote
0answers
234 views
pfsense Server Load-balancing on LAN Interface [closed]
I am trying to load balance a couple of web servers from the LAN side as I don't need access from the WAN so that clients on the LAN can access these web servers:
LAN IP is 192.168.10.1
I created a ...
6
votes
2answers
588 views
How does NAT work with incoming UDP packets from unknown IP
Apologies in advance for the relatively noob question and if this is off topic here ( I am not sure...)
The situation is that I have a UDP client and server bound to the same port.
My understanding ...
1
vote
1answer
67 views
Outbound NAT for single host behind an ASA located over an IPSEC tunnel [closed]
I have these two nets connected over the public internet with ASA 5510s.
192.168.0.0 < -- ASA1 ---> Internet <--- ASA2 --> 192.168.5.0
Each net does either a simple dynamic or static nat ...
1
vote
2answers
223 views
Leak default route to multiple VRFs while keeping VRFs isolated from each other
I'm working on a configuring stuff on a Cisco Nexus 3k based platform and trying to isolate different things into different VRFs which should not be able to talk to each other.
Some of these VRFs ...
1
vote
1answer
38 views
Connect office to multiple customer VPNs
First time post here so if this is off topic please let me know where to ask this question.
A company that provides outsource billing services to multiple client companies using VPNs to each remote ...
0
votes
2answers
114 views
Why does NAT keep track of each packet not just connections?
I have tried packet tracer and actual cisco routers and I find this weird: NAT uses different source ports, usually incrementally, for consecutive packets from the same connection. Why is that?
...
0
votes
2answers
72 views
How does the NAT work [closed]
I have a public ip assigned by isp, two phones are connect to wifi router. In both the phones i am seeing news feed on different facebook accounts, so facebook gets packets from only one publuc ip ...
2
votes
3answers
145 views
Why can't a host B act as a server, and accept TCP connections, when sitting behind a NAT?
Originally, I thought I intuitively understood why B can't accept TCP connections, however when I read about how P2P applications circumvent this exact problem by using an intermediate peer that is ...
2
votes
2answers
1k views
Why to use public IP addresses within private networks?
I have started to work in a multinational company which has a global network spanning across 4 continents (20 0000+ network devices).
I noticed that a lot of end user devices (PCs, laptops) have IP ...
2
votes
2answers
131 views
What is the point of outside NAT?
I understand how outside NAT works, but I do not know when it should be implemented?
Could you please tell me some scenarios when outside NAT is needed?
Thanks!
8
votes
2answers
798 views
routing between vlans not working
I need to put a Cisco router behind an ISP router.
(The ISP doesn't allow us to use their modem only.)
I've called the ISP technical service and they've set up the connection with me.
Their router ...
