Questions tagged [ipv4]
For questions about Internet Protocol version 4 (IPv4); as specified in RFC791.
709
questions
0
votes
0answers
8 views
How do I "remove the DHCP lease of my devices” from my TP-Link router [closed]
Details of the problems I ran into that lead me to do this is described in this question: https://apple.stackexchange.com/questions/382067/why-is-this-wi-fi-problem-happening-to-my-mac-and-iphone-...
1
vote
0answers
23 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
278 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
35 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
51 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
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0answers
13 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
8k 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
21 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
47 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
39 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
35 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
73 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
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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
42 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
38 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
115 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
72 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
147 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.
2
votes
1answer
42 views
Typical signs of fragmented IP fragments
Given, for example, a Wireshark trace, how can I identify that the IP fragments that I am sending are themselves being fragmented?
For example, if I'm sending 1500 byte IP fragments, and the server ...
2
votes
1answer
119 views
How does NAT ensure that every machine has a unique public IP?
I am trying to understand the distinction between public and private IP addresses in IPv4 networking. The picture I've been told has some problems with it, so I would like to present it here and ask ...
16
votes
4answers
5k views
Why is 10.1.255.255 an invalid broadcast address?
I’ve been following the CCENT official certification book(100-105) and came upon this question in the “do I know this already?” quiz. The books only covered /24 subnetting only so far.
Which of the ...
1
vote
1answer
83 views
Can communication to broadcast 224.0.0.1 be made to reach hosts outside of the local subnet?
I been asked the question if it is possible for an a IP host to use multicast to address 224.0.0.1 in order to reach (and get a response from) another host which is not on the local network segment ...
0
votes
1answer
35 views
When IP header of length 22bytes is there then how padding will work?
My base IPv4 header of 20bytes + 2bytes i used for Options making it 22bytes means 176bits so padding will add 16 Zeroes to make it multiple of 32? is this correct way to understand?
Boundary of ...
0
votes
1answer
58 views
Which IPv4 options must be copied on fragmentation and why?
In RFC 791 page 14 it says
The copied flag indicates that this option is copied into all
fragments on fragmentation.
0 = not copied
1 = copied
If I understand correctly it is possible ...
-2
votes
2answers
209 views
What's the DF flag mean in IP packet header?
In the IP package, there is DF flag: Don't Fragment.
I have doubt about it, is it mean let all the L3 device do not to fragment the IP packet (if the L3 device found it is bigger than MTU, device ...
0
votes
2answers
20 views
Can 2 Directly connected PCs having the same network ID but different subnet mask talk? [duplicate]
If Pc1 has IP 192.168.10.2 / 24 ---> Network ID : 192.168.10.0
and Pc2 has IP 192.168.11.3 / 23 ---> Network ID : 192.168.10.0
directly connected (no switches no routers).
Why cant i ping?
But if ...
-1
votes
1answer
59 views
Floating Number representation for Ipv4 address
I'm wondering if we can have floating point(3.3 9.9 2.2 6.3) or Hexadecimal(6A.65.D5.77) representation for Ipv4 address that is also 32 bit long to compensate for IPv4 address shortage. Same ...
2
votes
1answer
297 views
Why the IPv4 need Don't fragment Flag?
Why the IPv4 need Don't fragment Flag?
We know the IPv4 Flags options are: Reserved bit, Don't fragment, More fragments, fragment offset options.
Why there need the Don't fragment Flag? if it is ...
1
vote
1answer
48 views
How to understand the Flags is IP_MF, what will happen?
For data packets whose length exceeds the MTU of the interface, fragmentation processing is required. The fields related to fragmentation in the IP header are as follows:
Identification - Used to ...
0
votes
4answers
166 views
How do devices connected to a switch get their IPs?
It should go without saying, I'm new and still learning about networking. One of the things I'm not clear on and couldn't find a satisfying answer to, although I've done some digging around, is how ...
3
votes
2answers
198 views
Global BGP Routing only by only importing supernet prefixes
I was wondering if global IPv4 Routing can be technically achieved only by importing from the ISP Provider (providing us with a IPv4 BGP full table) a subset from the BGPv4 routes (i.e. all prefixes ...
1
vote
2answers
98 views
What information does the network and host components of an IP address indicate?
I understand that an IPv4 address is represented by 4 consecutive bytes:
<8bits>.<8bts>.<8bits>.<8bits>
And understand that this 32bit address comprises a 'host' and a '...
1
vote
2answers
212 views
Why do transport layer do data chunking. If there is fragmentation in Network Layer
I just curiously wanted to know about the question regarding L4, L3 Data Chunks, IP Fragmentation :
Data chunking happened at Layer 4(Transport, TCP), and
Fragmentation at Layer 3(Network, ipv4)
...
3
votes
2answers
725 views
What determines the private ip addresses? [closed]
Right now, I am using internet at home, and my private ip address is 192.168.x.x.
At work my private ip address is 10.x.x.x.
In both of the scenarios, I did not play any role in selecting my ip, I ...
0
votes
1answer
93 views
Scaling fragment offset
I studied that fragment offset has 13 bits. At transport layer segmentation is done considering the the MTU at lower layers (network layer, data link layer). Ethernet format says the maximum data ...
0
votes
1answer
44 views
Prevent Users from Setting Specific Static IP
I have an HP procurve switching environment in which users are often assigned static IP's. One user changed their IP to 172.17.1.1 which is the core switch VLAN 10 interface. Since all the users in ...
0
votes
1answer
41 views
Bringing two different hosts each in two different subnets into a same subnet [duplicate]
Physical Network: 11.11.10.0(mask:255.255.248)
Subnet A 1 :11.11.10.0 IP A: 11.11.10.4 (mask:255.255.248 and 6 hosts)
Subnet B 2 :11.11.10.8 IP B: 11.11.10.11(mask:255.255.248 and 6 hosts)
Hi ...
0
votes
2answers
62 views
Meaningless bits in CIDR notation
Is specifying meaningless bits valid syntax in CIDR notation? For instance, the netmask of 192.168.13.0/16 is 255.255.0.0. In this case, the last two octets (00001101 00000000) are meaningless because ...
0
votes
2answers
368 views
Why does yealink ip phone is not getting ip address from voice vlan?
I have configured separate vlan for voip and connected interface to it (as shown below). But the phone is not getting ip address automatically.
switch- cisco 2960-x
phone- yealink
I had tried: (on ...
0
votes
3answers
104 views
Why can my ISP use 172.39.29.71 as local network IP? [closed]
I just check my IP routing? and it turns to be:
IP:10.29.66.27 -> 172.39.29.71 -> x.x.x.x my outmost IP, which I get by Google "my ip".
As far as I know, 172.16.0.0/12 is the one of the 3 private ...
0
votes
2answers
61 views
Sending an ipv4 packet to the Destination IP without a router?
We are replacing a "RF modem + Router system" with a Software Defined Receiver.
After analyzing the receiving and sent signals we found out that an IPv4 UDP packets have been sent and received.
The ...
0
votes
1answer
64 views
What do you need apart from registering IP addresses to use them?
I need to connect to a certain Site from several public IP addresses (~1 million).
Assume that I am Bruce Wayne so I could spend several million dollars on this. The site at least for now is not IPv6 ...
2
votes
1answer
61 views
Is this possible (NAT??)
I have a device on another network, say it's IP is 10.1.1.1
I want to ping it from my own network, say host 192.168.1.1, but I want to ping an address in my local segment to do so,so 192.168.1.2.
Is ...
1
vote
1answer
45 views
Assign a new public and static IP to a router behind my main router [closed]
What can you suggest to bring a second public and static IPv4 so I can configure my WAN-A interfase with my primary and an additional secondary IP settings so I can route all the traffic from the ...
0
votes
2answers
81 views
Why can't we have duplicated IPs?
This may be a really dumb question, but I like to turn upside down what I already know sometimes, that way I can learn more.
For example, given a network 192.168.0.0/24, I have a device inside with ...
1
vote
2answers
39 views
How many public static ips do one need if a PC is behind a wireless router?
If a PC is connected to internet through a wireless router.
How many public static ips do one got to get from the ISP.
Do the router and PC both require one static IP.
What if I want to add more PC ...
1
vote
2answers
69 views
how do hackers get public ip off packet sniffing [closed]
That may be a dumb question but I am a student in computer science(security & networking) and I gotta find someone who can clearly explain this concept to me.
If the server of an app. 'x' is used ...
-1
votes
3answers
35 views
ACL for DNS clarification
I do not understand why the second ACL is needed if all I want is to ensure all networks use a certain DNS server (for example 192.0.2.1)
access-list 112 permit udp any host 192.0.2.1 eq domain
...
