Questions tagged [ipv4]
For questions about Internet Protocol version 4 (IPv4); as specified in RFC791.
739
questions
-2
votes
0answers
13 views
RESEDENTIAL IP OR DATACENTER IP, how to only allow only real humans (without using reCAPTCHA or any such)? [closed]
how do i figure out if a HTTP request to my website is by a real user? in other words, what are factors that determine if IP is a residential IP or data-center/hosting/commercial IP? is only geo-...
0
votes
0answers
15 views
IPv6 Hardware and Software [closed]
what are the impact of the introduction and use of IPv6 on hardware and software, mainly focusing on switches and routers?
-1
votes
0answers
21 views
Why do I still get public IPv4 address whenever I move even though we’re running out of them? [closed]
I have done some google search and could not find any good explanation. I have the background of networking, but isn’t Comcast running out of IPv4 addresses? If so, that means I must have shared my ...
0
votes
0answers
16 views
Why does the IPv4 datagram header contain a `Total length` field instead of having a `Data length` field? [closed]
Based on RFC 791 and Data Communications and Networking, V Edition, I can say that Total length helps in fragmentation process. And because of that, the value of MTU also focuses upon Total length. We ...
0
votes
2answers
30 views
why ip protocol use fragment offset instead of index number?
I was wondering why the IP protocol use fragment offset to define the fragments of an IP datagram instead of using index number (first fragment with index 0, second with index 1, ...). We already know ...
0
votes
2answers
43 views
Can a host from different subnet bypass the network mask validation of destination host and communicate on layer 2?
I am aware that a host will always check the subnet of the destination node before the transmission in order known if it has to send it to the gatewey for different subnet.
However, would it be ...
0
votes
1answer
23 views
Understanding IP scheme, distribution and usage [duplicate]
I'm new to networking and I'm doing my best to understand how things work. I do have a problem in understanding IP scheme idea (even though obsolete), more specifically, their structure, distribution ...
0
votes
0answers
9 views
How to calculate the prefix of an IP Address? [duplicate]
I know there are many questions/answers for this already but i'm really confused on how the prefix of an IP is calculated. I'm currently doing an mock paper for an exam and the question goes like this:...
0
votes
1answer
24 views
How can I assign a static public ip to a machine behind a router?
I know about port-forwarding, but I'm interested in how to make a machine on a local network available to the public internet without port-forwarding.
0
votes
1answer
24 views
Default subnet question [duplicate]
Very new to network engineering. I just watched a really good series of videos on YouTube explaining IP addresses, subnet masks and the class system for IPv4.
There was one bit which got me confused ...
24
votes
3answers
5k views
Will IPv6 make private IP addresses become obsolete?
Will it still be useful to make use of private IP addresses with IPv6?
0
votes
1answer
48 views
I don't understand IP addressing for a router
I am taking an internet (CISCO) course and don't understand the difference between the default gateway address for a router and its IP address. In every example of the class the default gateway ...
0
votes
0answers
9 views
Determine the range of IP's avaliable for hosts on a subnet /28 [duplicate]
I am looking into my Virtual Switch configuration( Hyper-V ) and i am confused how the range of valid IP's is determined.
The IP for configured for the "Virtual Switch" adapter is:
IP: 192.168.53.65 ...
2
votes
2answers
205 views
transferring IPv4 /32 to another datacenter
We are planning to migrate one set of IPv4 /32 series owned by us, from one dedicated server provider to another provider. Is it necessary to have permission to release the IP series from previous ...
1
vote
0answers
25 views
If a server has both IPv4 and IPv6 addresses, how does the DNS determine which to return? See the following example [closed]
These Pings were done at different times of the same day:
C:\Users\LPress>ping www.ucla.edu
Pinging gateway.lb.it.ucla.edu [164.67.228.152] with 32 bytes of data:
C:\Users\LPress>ping www.ucla.edu
...
4
votes
4answers
353 views
Layering unicast addressing over multicasts
My question has to do with layering of unicast over multicast and has two parts.
Part 1. IP unicast over MAC multicast
First part of the question is whether there is a standard that prohibits use of ...
-1
votes
1answer
37 views
Able to ping Domain internal address on home network, why? [closed]
I have a strange issue, I am able to ping my company's internal address (ex: hq.mycomapny.com) when I am on my Home network (WI-FI or Enthernet) and NOT connected to the VPN.
When I do a ping on the ...
0
votes
0answers
18 views
Are network IP addresses ever used as source or destination IPs? [duplicate]
The first IP address of an IP subnet is the network address, which stands for the whole network, while the last address is the broadcast address.
As far as I understand, we never really send packets ...
1
vote
1answer
46 views
IPv4 maximum datagram size
The IPv4 datagram consists of two parts:the header length and the payload. The maximum header size is 60 bytes and minimum is 20 bytes. The maximum size of the data can be 65515 bytes. So why the ...
1
vote
1answer
144 views
Broadcasting to unknown Class C Network
I am trying to use python to broadcast to my local network, and I cannot find a way to get the subnet mask. I have been suggested to use the default Class C network subnet mask 255.255.255.0, and use ...
1
vote
2answers
45 views
Where are broadcast packages filtered out
When I have one network with a switch. Within that network I have 10 PC. Halve of them are configured within the 192.168.1.0/24 range and the other halve is configured at 192.168.2.0/24.
This means I ...
0
votes
1answer
38 views
Find Routes not containing these subnets [closed]
Let's say I have 1000 ranges and I would like to make routes that doesn't match these ranges, anyone has any particular tips or tools to share beside doing math ?
Example :
I have these ranges
13....
2
votes
1answer
63 views
Why Classful addressing is not in use if we can subnet them?
So,
Let's think that organization needs 5000 IP addresses. Giving 20 C Class IP addresses will cause of adding 20 entries for ISP router. That's problem. We could give Class B IP address, but that ...
0
votes
0answers
19 views
How to find minimum of hosts bits needed and assign equally to five subnets? [duplicate]
I have a 192.168.1.0/18 network block. How do I determine the minimum number of host bits to be borrowed and assigned equally to five subnets? How to calculate the number of users that can be ...
2
votes
2answers
53 views
The MSB of IPv4 flags
In IPv4 header, there is 3 bits field called "flags". The MSB of this field must be reset to zero (as many networking blogs say without telling why).
i want to know what will happen if I managed to ...
0
votes
2answers
57 views
Do NAT devices need to have private IP addresses?
If a NAT's job is to create mappings between internal ip/port pairs and external ip/port pairs with one Internet-routable IP address, does a NAT need a private IP address for itself? I think one ...
0
votes
2answers
141 views
Routing Table Settings To Access An Internal Network Through VPN
I have a remote computer behind a VPN (which I have no control of). The IT team of the remote factory wanted me to install Palo Alto Networks' Global Protect program to access the VPN, which is ...
0
votes
1answer
70 views
Can I run 2 separate ranges on the same physical network
My current set up is 1 router and 2 switches, the router being 192.168.10.1 with a connection to each switch then 8 and 10 devices on the 2 switches all 192.168.10.x
I have an NVR with 2 ports, 1 of ...
0
votes
2answers
60 views
When a packet is received, how does it know which internal machine to send it to?
I am familiar with ARP and routing, but I think I am failing to put two and two together here. On an IPv4 packet we have the source IP address, which allows any router to send the response back to the ...
2
votes
1answer
42 views
Is an IP broadcast always a layer 2 broadcast also
On my PC I see 255.255.255.255 in ARP with MAC FF:FF:FF:FF:FF:FF, so I'm assuming that in most cases the L3 broadcast is also encapsulated into an L2 broadcast frame, but is this standardized?
For a ...
0
votes
2answers
58 views
Why can some people use public ip address to access a server from an internal network with the client device within the internal network
As the title suggests. I find it mind breaking to think how network architecture can differ to allow/not allow using public IP address to access a server within internal network from within the ...
1
vote
0answers
32 views
How can I configure a Cisco router 4300 to allow internal server ip:80 to be accessed on public ip:4500
I have an internal web server on port 80. I need help commands maybe to configure port forwarding to access the server on my private network from a public IP
Current running config
interface ...
1
vote
2answers
404 views
MTU the most Confusing Networking term. Lot of questions
I have ton of questions and i feel this is most confusing term for me. The more i read the confusion deepens.
I am not able to connect dots. please help.
Do we need MTU adjustment with EoMPLS/dot1q ...
1
vote
1answer
40 views
IPv4 Subnetting for 1200 or more devices for WiFi
I am currently looking over my schools existing Subnets and their usage. Some seem to be sufficent, others not so much.
What is the best practice when you need to support 1200 or more devices on a ...
1
vote
2answers
90 views
Question about the destination IP inside an IPv4 packet
I'm reading about link and network layers for the first time and I'm trying to put the pieces together to understand how they work together. My question may not have to do with the link layer but I'm ...
0
votes
0answers
9 views
Given a subnet mask, how can I determine which addresses can be assigned to public network hosts? [duplicate]
For example, I'm given a subnet mask of 255.255.255.248 and need to determine from a list -
16.70.118.63
134.178.18.56
200.47.224.159
68.111.178.93
192.168.16.87
217.37.10.192
- which addresses can be ...
0
votes
0answers
14 views
Building simple network configuration [duplicate]
For the below network configuration I need to propose an IP addresses, netmask and anything else obvious that I am possibly forgetting.
The network is built of four Computers, Router and a Switch. I ...
17
votes
5answers
9k views
Usage of 192.168.xxx, 172.xxx and 10.xxx in private networks
I know that the organization that distributes IP addresses decided to assign 192.168.xxx, 172.xxx and 10.xxx to private networks. However, I thought that private networks have their own address space ...
1
vote
0answers
24 views
Is it possible to access 127.0.0.xxx in anyway [closed]
So I've been configuring my network at work. We've got a lot of devices from NAS servers to Dante AoIP devices.
While configuring some of my devices I managed to set the IP adress of one device to ...
5
votes
3answers
2k views
Does NAT violate end to end argument?
Does NAT violate end to end argument?
What does end to end argument means in this context?
2
votes
0answers
56 views
How is it possible to have a default gateway outside of the network range of any interface? [closed]
I always thought that the default gateways has to be on the same network as the server/client trying to connect to the internet. However today I rented a server from Hetzner and the server is able to ...
1
vote
2answers
47 views
How TCP connections between origin and node servers over a BGP Anycast gets established?
Server A and B have the same IP address with anycast. Server B connects to the origin server that is very close to server A and very far away from server B, since server A is closer, the response will ...
0
votes
1answer
61 views
Remotely Connecting an IPv6 Computer to a IPv6 Private Web Server
I have a private web server at my office, and I want to access that server remotely at my house via IPv6.
My office has both IPv4 and IPv6 enabled, but my home has only IPv6.
IPv4 works, but I have ...
0
votes
2answers
111 views
Loopback with / 32
When we dealing with bgp, osp. Why do we especially use loopback interfaces with / 32!?
Is there an advantage or something different from other subnets like 24.
0
votes
0answers
11 views
Why is the source / destination address ordering in IPv4 and IPv6 headers opposite of Ethernet source and destination MAC addresses? [duplicate]
Engineers always do things for a reason.
I've noticed that in Ethernet frames, the ordering is destination MAC address first, and then the source MAC address.
What's the reason for reversing the ...
0
votes
1answer
43 views
Setting the network address freely [duplicate]
I'm trying to understand IP Addressing, but there's something what's still not clear for me.
With mask
1111111.1111111.1111111.00000000 (/24)
Am I able to set network address "freely" like this?
...
1
vote
1answer
49 views
Next Header field in IPv6 vs Protocol field in IPv4, any difference?
So I am new to the IPv6 concept, and I seen that the Protocol field seems to be replaced with Next Header, and I have a question.
Question:
Is Next Header a complete replace of Protocol, or is they ...
1
vote
3answers
120 views
What is the intuition behind subnetting a base IP?
Take a look at this picture:
My professor usually gives a topology like this and gives me a base IP. Let's say the base IP given is: 223.1.0.0/24. We're then asked to construct the given topology by ...
2
votes
1answer
87 views
Confusion about IANA “Protocol Numbers” registery
In the IANA registery for "Protocol Numbers", there listed 2 IP protocol versions: IPv4 at #4 and IPv6 at #41. Their "protocol" column says IPv[46] Encapsulation, and "reference" column points to 2 ...
2
votes
3answers
216 views
Will pinging the multicast “all hosts” IP 224.0.0.1 fill my ARP cache with all hosts on my current subnet?
Just wondering in case I ever have a want / need to see all the hosts on my subnet.
