Questions tagged [ip]

For questions about Internet Protocol (IP), an OSI layer-3 network protocol. There are two current IP versions in use: IPv4 and IPv6.

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51 views

How to do subnetting on IPV6 for non nibble boundaries?

As I was reading this article on How to: calculating IPv6 subnets outside the nibble boundary https://blog.apnic.net/2018/08/10/how-to-calculating-ipv6-subnets-outside-the-nibble-boundary/ The author ...
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0answers
11 views

Linksys E1200 Gateway [on hold]

I received static ip data from the provider. It's like this: ip: x.x.x.1/31 sub: 255.255.255.254 gateway: x.x.x.0/31 DNS: x.x.x.x and x.x.x.x When I try to enter the gateway in linksys E1200, it ...
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0answers
13 views

Accessing my server through work networks [closed]

So before I explain this.. this is something I am allowed to do at my work.. So I am not breaking any sort of rules in that sense! I have a simple server running on my Mac. I then forwarded ports on ...
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1answer
27 views

Remote Host Neighbor Cache Entry State after Neighbor Solicitation request

When a Host A sends for the first time a NS request to another Host B, host B answers with a NA. In Host A Neighbor Cache, the state Entry for host B gets from INCOMPLETE to REACHABLE, when NA comes ...
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2answers
68 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 ...
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2answers
65 views

Why does Nmap not detect a host which is active and responds to Ping?

I have connected to another laptop via the LAN cable, i am able to access the services running on the other laptop via Ip & Port. When i Ping that Ip, the machine is successfully responding. But ...
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1answer
37 views

IP Camera (CISCO Packet Tracer)

I've been asked to simulate a topology, which requires me to implement 2 CCTV cameras in a network using Packet Tracer. However I realise that their isn't IP Cameras in PT, so how best can I simulate ...
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1answer
69 views

How does IP assignment work for servers and data centers

If I had an IP address (for example bought range for my company), and 2 ISPs fibres, how would it be possible to set my network card to have same IP adress accessible from both connections? (know its ...
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1answer
13 views

Varible Length Subnet Masking - Smaller subnet with two larger subnets on each side?

Background: I'm redesigning a network of virtual machines. The virtual machines are all on 10.0.2.0/24 and 10.0.3.0/29 networks, the physical network is a 172.32.255.225/28 network, which stands ...
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6answers
4k views

Could IPv6 make NAT / port numbers redundant?

From what I can tell, each process could get its own IP address, with loads of IP's to spare. What would the drawbacks be? Essentially, your host would become a router and each process is a host (in ...
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6answers
4k views

Why do I need to specify a subnet mask on interface?

When assigning an IP address to an interface, why do I need to specify a subnet mask? I understand the purpose of subnet masks in a routing table for example (to specify a range of IP addresses as ...
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1answer
29 views

What happens if we try to access an IP Address that does no exist

Beginner Question: I just read an article talking about how the internet works and how routers make sure that packets arrive at the destination. However there is one thing that is not explained ...
2
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1answer
70 views

Setting Destination MAC address for RTP/UDP packets

I have a requirement where I have to send the UDP packet to a destination multicast IPv6 address. In addition to that the packets must also have corresponding destination multicast MAC address set. I ...
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0answers
19 views

routing with multiple NICs (connected to multiple APs) that were all assigned the same LAN address [closed]

I have 4 wireless APs based on the ESP8266. These APs all broadcast distinct SSIDs, but each serves LAN addresses in subnet 192.168.4.XXX. The subnet value is not configurable. Then, I have a Linux ...
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3answers
2k views

Usage of Flow label in IPv6 header?

I have been reading the IPv6 Flow Label Specification (RFC 6437) and I would like to ask about the purpose of setting this label. In case of just using the 2-tuple (source address, destination ...
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2answers
73 views

How does cellular data differ from an ISP, and what can be tracked?

Are IP addresses given to a phone static or not? Also, how can phone companies keep track of a person if they wanted to find them? For example, I don't have an account and use a pre-paid card. I'm ...
1
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2answers
44 views

Does an IP address with host part zero's represent a network, or a network interface in a network?

If the host part of a IPv4 address is all zero (e.g. 192.168.1.0 in a network with mask 255.255.255.0), does the address represent the network, or a network interface in the network? Thanks.
2
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1answer
38 views

Why does TCP need segments if the network layer automatically breaks things up into fragments?

I'm trying to better understand the difference between IP fragments and TCP segments (https://www.shubhsblog.com/tech/difference-ip-fragmentation-tcp-segmentation.html) and there's one thing I'm not ...
0
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1answer
46 views

How to get a static IP address? [closed]

I need to get a static IP address to access to a service that only allows specific IP (I can manage the whitelist). The problem: my public IP is dynamic. I'd like to : be able to activate this ...
0
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0answers
13 views

IP block assignment [duplicate]

Let's say that an ISP manages the IP block 128.64.32.0/19, and assigns the block 128.64.32.0/22 to company A. Now, company B needs a block of IP addresses for 1234 hosts, immediately after the IP ...
2
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2answers
56 views

Do extension headers in IPv6 increase the header length

I was reading about IPv6. It says the header is of a fixed size i.e. 40 bytes, then how come is it able to accommodate extension headers. Doesn't this alter the size of headers. Please help, cant ...
0
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1answer
27 views

localhost vs local IP address: traffic flow [closed]

Let's say I have a server with IP address 192.168.0.1 that is running a network service (I don't think it is important what kind - let's say a webserver on port 80). If I am on the server itself and ...
2
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2answers
51 views

How to handle ICMP-in-IPv6 or ICMPv6-in-IPv4?

Since ICMP and ICMPv6 have different IP protocol numbers, it's technically possible for an IPv4 host to receive an ICMPv6 packet or for an IPv6 host to receive an ICMP packet. Is the host's behavior ...
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2answers
2k views

IP addresses from public IP block in my LAN

If I have NAT or PAT applied on edge router, Would it matter if I use IP addresses from public block in my LAN? And how?
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1answer
31 views

How to tell apart the type of the mask(subnet-supernet-net mask)

Say we have the the IP address 10.2.8.230/24 Anyone could say the following: It just represents a normal network:10.2.8.0/24 Or it is a subnet because normally this IP address is in the class A ...
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3answers
123 views

Is IP an abstraction

If packets "hop" from network device to network device across networks using MAC addresses, resolved by ARP, does this suggest that IP is essentially an abstraction? By abstraction, I mean, the ...
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2answers
18k views

Ip fragmentation and packet headers

I read somewhere that a fragmented ip packet can further be fragmented depending on the changes in the network. Now how is the packet reassembled at the router. Because the identification bit can be ...
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2answers
63 views

What does it mean when the last digits of an IP address change? [closed]

So in a case where I have an IP address, 162.158.68.xxx, what is happening when those values in xxx change? I ask because I'm looking at requests going through to my application's server and one of ...
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2answers
42 views

Addressing for a WAN, LAN and DMZ

I was wondering about the addressing for certain types of networking areas... I use 192.168.0.0 for a LAN network, 10.0.0.0 for a WAN and 172.16.0.0 for a DMZ. But I've been confused why a 10.0.0.0 ...
2
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1answer
74 views

Using an Ethernet cable and USB Ethernet adapter at the same time?

What would happen on using an Ethernet cable connected to one network and then plugging in another Ethernet cable but using an USB Ethernet adapter from a different network. Would it connect to both ...
1
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1answer
25 views

How do devices with static IP behave themselves when plugged to a new network? [closed]

I'm trying to understand how to determine if a device plugged to my PC with Ethernet cable has a static IP. What I'm trying to do is to sniff DHCP packets that it sends and by looking at DHCPDISCOVER ...
2
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2answers
49 views

ACL: Deny specific host not working

I'm trying to create an acl for use with a nat but I can't get the deny statements working. All hosts on a private network should be accessible, except from a server which should not be accessible ...
2
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2answers
724 views

ARP table is not updated with NMAP

Here is what I do and what happens : Let assume I have a device A with IP X.X.X.200 connected to the network I use Nmap to ping my local network, with the command "nmap --send-ip -sP 192.168.1.1/24" ...
0
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0answers
16 views

IP SLA Flow generator (udp-jitter)

I study IP SLA because i want to test my network for VoIP. I found an article who show a study of " Scalability of Layer 3 Tunneling Protocols: Case of Voice Traffic Over IP". "Based on this project ...
2
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5answers
26k views

How can 2 computers in different network communicate?

Suppose my friend and I are connected to the Internet via some local ISP (not necessarily same), which means we are on different networks, hence our computers have different private IP addresses. Is ...
5
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2answers
155 views

How to architect a globally distributed website, from an IP address perspective

I would like to have a website that is loaded fast from any point in the world. From my understanding, you need to take advantage of the data center "regions" at places like Google Cloud or AWS. That'...
2
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3answers
76 views

Is it possible that two servers were configured with the same ip under the same switch

I have two physical servers, their configuration as following: ServerI: IPADDR=10.1.1.5 NETMASk=255.255.255.0 ServerII: IPADDR=10.1.1.5 (Same IP) NETMASk=255.255.0.0 (different NETMASK) Because of ...
3
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1answer
79 views

Public and Private IPs

I wondered if someone could explain this to me. At work we have a firewall that connects to the Internet and has an external IP configured on it via DHCP. The firewall's WAN port connects to an ...
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1answer
28 views

why can't we use the sequence number to distinguish them since every packet has a different sequence number? [closed]

It is a question from Networking stanford course. A server typically listens for TCP connections on a particular port (e.g. 80 for HTTP or 22 for SSH). Which fields can the server use to ...
0
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3answers
59 views

What IP address can't be the source address in a packet?

I heard that the destination address in a packet can't be 0.0.0.0. Is there any IP address (including special ones) which can't be the source address in a packet? Thanks.
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0answers
21 views

Which fields can the server use to distinguish packets for a particular client connection? [duplicate]

A server typically listens for TCP connections on a particular port (e.g. 80 for HTTP or 22 for SSH). Which fields can the server use to distinguish packets for a particular client connection?It is a ...
0
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0answers
20 views

Unable to calculate for subnet mask [duplicate]

My question is - To divide a class C network into a maximum of 14 subnets each capable of having up to 14 hosts, the subnet mask used should be .. what and how ?
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0answers
20 views

Questions about IP addresses [duplicate]

So, I have to research IP addresses, and there are a couple of things I don't quite understand. In my test there will be questions like 'Which of those IP-addresses is private' or 'which of those is a ...
11
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6answers
12k views

IPv4 Segment 100.64.0.0/10

I recently got to know that IP segment 100.64.0.0/10 has been reserved by IANA for 'Shared Address Space'. My question is: Can I use the IP Segment 100.64.0.0/10 as a private range in my network (...
2
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1answer
44 views

IHL(Internet Header Length) field is 4 bit long and specifies the header length in 32 bit words. What does it mean?

I am trying to understand IPv4. I cannot understand
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2answers
34 views

what does the flag and mtu means in here

Reading some logs from my system it states eth0: flags 4163 < up, broadcast, running, multicast> mtu I am not sure what is the meaning of the flag here down below I see eth1,2,3 has the same flag ...
7
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2answers
912 views

Why do IPv6 unique local addresses have to have a /48 prefix?

According to RFC 4193, unique local addresses will always have a prefix of FD00::/8.. but according to Wikipedia: The block fd00::/8 is defined for /48 prefixes, formed by setting the forty least-...
92
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6answers
580k views

How do you calculate the prefix, network, subnet, and host numbers?

Example: IP: 128.42.5.4 In binary: 10000000 00101010 00000101 00000100 Subnet: 255.255.248.0 How could you determine the prefix, network, subnet, and host numbers?
11
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3answers
1k views

Are the IPv6 address space and IPv4 address space completely disjoint?

Tanenbaum's Computer Networks says Finally, IPv4 addresses can be written as a pair of colons and an old dotted decimal number, for example: ::192.31.20.46 Does it mean the IPv4 address space ...
2
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1answer
41 views

What can an IP address be assigned to?

What can an IP address be assigned to? A network interface, which is what I thought originally. (I seem to hear a network interface can have multiple IP addresses assigned to it, and if it is true, ...