Questions tagged [nat]
For questions about Network Address Translation (NAT), a method of modifying network address information in IPv4 packet headers.
0
votes
1answer
13 views
NAT from a non default gateway router [on hold]
I have a network with two different routers, like this:
Router1: WAN 1.1.1.1 LAN 10.0.0.1
Router2: WAN 2.2.2.2 LAN 10.0.0.2
PC1 (Windows 7) : LAN 10.0.0.11 GW: 10.0.0.2
PC2 (Windows 10): LAN 10.0.0....
0
votes
0answers
19 views
Route traffic through SRX without destination NAT
I'm trying to allow hosts in the untrust zone to access some server resources in the trust zone. There is some port overlap between servers that is causing problems with destination NAT. What I'd like ...
0
votes
0answers
20 views
Problem in NAT Outside configuration [closed]
im learning networking in my course. i followed NAT course in this site NAT PROBLEM . i did the setup as in the diagram then setup the NAT on R2 as mentioned in the page. I didn't do routing because ...
0
votes
0answers
11 views
Personal Wifi Hotspot — Public IP of connected devices [closed]
Network SMEs, I am kinda confused with what I am seeing with my hotspot connection on my iPhone (ios ver12). Connecting laptop (windows 10) to internet via iphone hotspot.
I used google to see what ...
-1
votes
0answers
13 views
Can I have more than one outside object point to one inside object?
I have a NATed SFTP server that gets packets from the firewall (Cisco ASA 5505) from the public address of x.x.x.207 and I want the SFTP{ server to also get SFTP packets sent to x.x.x.209. In my ASA ...
1
vote
1answer
53 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
18 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
14 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
319 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
97 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
3answers
60 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
141 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
29 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
47 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
45 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
156 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
42 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
160 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 ...
55
votes
7answers
14k 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
36 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
33 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
273 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
101 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
56 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
88 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
609 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
119 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
334 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
48 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 ...
0
votes
0answers
169 views
what is a reverse nat and why would i need it? [duplicate]
Though I could find some definitions of reverse NAT (like from here), I couldn't really understand why it is needed. I'd really appreciate some examples. And please don't get confused with the "...
0
votes
2answers
129 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
30 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
95 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
62 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
120 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
803 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
116 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
725 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 ...
2
votes
1answer
440 views
Configuring the NAT 1:1 rules with pfsense
I have two pfsense. One pfsense is on 192.168.0.1 and another pfsense is on 192.168.20.1. Basically I have installed 20.1 pfsense on one machine 192.168.0.180 which is in the network of 0.1 pfsense, ...
1
vote
1answer
28 views
Why specify additional NAT rule
In watchguard's guide for NAT loopback when describing the additional nat rules required, they show this image:
Why are those top two NAT rules necessary, ie aren't they already covered by the next ...
0
votes
2answers
57 views
IPSec - NAT-T inner/outer IP of the gateway?
I was configuring an IPSec VPN and somehow I can't figure out what the inner/outer IP of my gateway would be.
Have a look at this image :
Imagine I have my site-to-site VPN, with my gateway having ...
0
votes
1answer
32 views
Discovering public ip from wifi signals, shodan, parent router NAT [closed]
MAC addresses innately do not change right?
and you're able to scan for broadcasting APs where you'll be able to detect different nearby mac addresses of each AP..
Public IP addresses change, ...
2
votes
1answer
61 views
Asa5508 NAT two internal IPs
Hello I have a Cisco asa5508 and I want to NAT 2 internal IP's to 2 public IP's that I have.Each IP on its own.
Currently I have NatPool and it's working either with the one IP or with the other.
Is ...
-1
votes
1answer
84 views
Is NATing possible in case of IPV6 addressing mode anyway?
Setup:
A(2001::1:123) <------> B(2001::1:124) <------> C(2001::1:125)
where A,B and C are the systems.And apply rule of NAT(SNAT/DNAT) on system B for forwarding a packets from C to B,B to C,A ...
-6
votes
4answers
2k views
What is the difference between DHCP and NAT?
Both seem the same to me. I don't see how DHCP is different from Dynamic NAT. Can anyone please help?
1
vote
1answer
68 views
2 Wan DHCP to cisco router
I have a cisco 2921 router and 2 wan ips provide by 2 diferents isp via dhcp. The main connection is funtional right now, I have a subnet with a nat to this ip, but I want put the second ip just to ...
1
vote
1answer
272 views
ASA VPN Tunnel NAT Issues
I've been trying to jump through two tunnel.
A Customer has a cloud solution which we need access to.
Since we already have a vpn site2site tunnel to the customer we can already access his LAN. What ...
2
votes
2answers
83 views
How does/did an ISP serve so many people over IPv4
Whilst reading Tanenbaum - Computer Networks they talk about IP scarcity at the level of ISPs:
IP addresses are scarce. An ISP might have a /16 address, giving it 65,534 usable host numbers. If it ...
