Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
1answer
24 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 ...
0
votes
0answers
9 views

Multiple DHCP servers detected by access points [on hold]

I’m having an issue with our internal network and voip network. I currently have it setup as a non-converged network separating our two data switches and one voip switch. We preferred not having our ...
2
votes
1answer
57 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 ...
1
vote
0answers
18 views

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

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 ...
2
votes
1answer
35 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
votes
1answer
39 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
votes
1answer
29 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 ...
0
votes
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 ...
0
votes
1answer
25 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
votes
2answers
47 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 ...
2
votes
2answers
45 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 ...
4
votes
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?
1
vote
1answer
30 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 ...
1
vote
3answers
119 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 ...
0
votes
2answers
43 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 ...
0
votes
2answers
37 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
votes
1answer
69 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
vote
1answer
24 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 ...
0
votes
0answers
15 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
votes
2answers
44 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 ...
5
votes
2answers
145 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'...
1
vote
2answers
69 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 ...
3
votes
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
votes
1answer
77 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 ...
-1
votes
1answer
26 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
votes
0answers
18 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
votes
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 ?
0
votes
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 ...
1
vote
2answers
41 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
votes
1answer
29 views
0
votes
3answers
57 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.
7
votes
2answers
852 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-...
0
votes
2answers
33 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 ...
2
votes
1answer
39 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, ...
11
votes
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 ...
1
vote
1answer
27 views

Public IP addresses on cloud platforms [closed]

My question is about cloud platforms like AWS or Azure. Whenever we create an instance (VM or VPC), AWS allocates a set of public and private IPs for that instance. Now the number of user accounts (...
1
vote
1answer
71 views

Switch Configuration for Connecting LAN and WAN

Totally new on networking and on switches, so excuse me if I use some wrong terminology. Problem I have 1 computer and 7 instruments. I would like to form a network setup fulfilling the following ...
7
votes
2answers
2k views

What is IP squat space

I came across this article and I'm trying to understand what is going on here, I found some packets on my network containing 22.0.0.0/8 and 29.0.0.0/8 IP range and It's based on: https://en.wikipedia....
3
votes
1answer
61 views

Host IP address vs gateway IP address vs DHCP IP address

What is the difference between a host IP address, a gateway IP address, and a DHCP IP address when setting up networking devices? For example, when configuring a virtual network adapter for my VM, I ...
0
votes
2answers
30 views

How does a router know it's received an OLSR message?

So I'm working on my own routing protocol based on a alternative to IP, called ILNP, and I'm having trouble understanding how a router differentiates control packets and data packets for OLSR. The IP ...
3
votes
1answer
109 views

What happens if the IP MTU is smaller than the MSS?

Let's say i configure the MSS > IP MTU. Even if it doesn't make sense, would this be possible? Assuming i then try to send a file of the size of MSS or bigger, the network layer will receive the data ...
1
vote
1answer
36 views

IPv4 only host on a dual stack environment

I am looking into migrating to IPv6 at my company. Our plan is to dual-stack everything for now, however, we have a couple of local servers that are IPv4 capable only. The rest of our network will be ...
0
votes
1answer
52 views

OSI Model vs Network Model: Does It Matter Which One You Use?

The OSI (Open Systems Interconnection) model is comprised of the following layers: 7. Application Layer 6. Presentation Layer 5. Session Layer 4. Transport Layer 3. Network Layer 2. Data Link ...
1
vote
1answer
36 views

Where is the block which caused IPV4 client can not access IPV6 Server

I read many documents which are saying if you are in IPV4 network then you can not access IPV6 network, for example when I was at home I can not access some IPV6 website, such as:ipv6test.google.com. ...
6
votes
2answers
2k views

Why maximum length of IP, TCP, UDP packet is not suit?

From many tutorials, I get follow knowledge(maybe I'm misunderstood) : maximum of an Ethernet packet is about 1500 bytes. maximum of an IP packet is about 65535 bytes. maximum of a UDP packet is ...
0
votes
0answers
16 views

Why maximum length of IP、TCP、UDP packet is not suit? [duplicate]

From many tutorials, I get follow knowledge(maybe I'm misunderstood) : maximum of an Ethernet packet is about 1500bytes. maximum of an IP packet is about 65535bytes. maximum of a UDP packet is 65515 ...
3
votes
1answer
42 views

ip dhcp class command

Here is a DHCP configuration that we have here: ip dhcp class range ip dhcp pool abc network 10.10.10.0 255.255.255.0 default-router ... class range address range 10.10.10.10 10.10.10.254 My ...
7
votes
4answers
1k views

Does every host on the LAN share the same ARP table, or do hosts keep them individually?

I'm just learning about ARP. I'm a little bit confused. My confusion is better explained in a scenario. Host A is communicating with Host B. Host A knows Host B's IP address, but not it's MAC address....
6
votes
2answers
922 views

How do routers on the backbone avoid IP address conflicts?

As the title suggests, how do ISPs, and other networks connected to the backbone ensure that their host network address isn't already in use by another backbone node, as there is no controlling device ...
4
votes
1answer
367 views

Will the packet be dropped when the number of hops equals to default TTL?

From my understanding, the default TTL represents the maximum number of hops allowed such that the packet may reach the host. NTP Documentation Archive: ttl - This option is used only with ...