Questions tagged [ipv4]
For questions about Internet Protocol version 4 (IPv4); as specified in RFC791.
782
questions
0
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3 views
Find out location of public IP address
Recently we have fallen into a discussion with a company that provides us SaaS solution.
We like to have our requests directed to servers in Europe, instead of USA to have better performance. So they ...
0
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2answers
14 views
rules regarding IPV4 fragments and piecing them together
I'm rolling off my own TCP/IP stack for DOS and I have a question on IPV4 packets.
Assuming that a client sends multiple IPV4 fragments, I would predict the MF flag would be set for every fragment ...
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1answer
42 views
How is the subnet mask detected over the internet with CIDR (classless inter domain routing)?
Lets say there are two public IP addresses. One is 21.120.12.8/16 and the other is 21.120.12.8/8, they are different network IDs but when used over the internet how are they both differentiated? Or is ...
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0answers
14 views
Device discovery [closed]
I have a GSM modem/router for industrial purposes. I forgot which ip and subnet it uses and it has no easy reset button. The manufacturer has a small application which instantly finds and lets you ...
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0answers
8 views
Extract Palo Alto ACC stats in text format
I have a Palo Alto p220 firewall, which acts as a virtual router at the same time. I would like to get the traffic data (download/upload in bytes per IP) in a format, which I could then parse on my ...
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1answer
32 views
What is the maximum number of networks in IPv4?
From my understanding, in IPv4 addressing, the first 2 octets identify the network, meaning 2^16 networks can exist. But that doesn't seem even closly enough as the population in even USA is above 300 ...
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2answers
47 views
Basic conceptual questions about network interfaces
I have some basic questions as I am trying to understand the concept of network interfaces a bit better.
Is network interface same as network interface card (NIC)? If not, what's the difference.
What ...
5
votes
2answers
660 views
Can a client-side outbound TCP port be reused concurrently for multiple destinations?
Can a client-side outbound TCP port be reused concurrently for multiple destinations?
If it's possible, this would let NAT gateways milk an IP Address much more, and make it practically impossible to ...
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0answers
26 views
ECT Marked ICMP Responses
For ongoing research I'm conducting, I'm measuring the modification of ECT fields of the IPv[46] header. To do this I'm relying on ICMP quotations to inspect what packets 'look like' as they traverse ...
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0answers
10 views
Into how many subnets can you split this address range up at most? [duplicate]
Let's say there is address range given: 124.33.66.0/23.
Into how many subnets can this address range be splitted up at most if each of these subnets includes at least 5 devices?
I don't know where to ...
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0answers
16 views
Why did we not run out of IPv4 adresses yet? [duplicate]
I know how IP addresses work and I also understand the reasons why there is a natural limit to those addresses, as well as the solution to that problem. Officially, we have ran out of IPv4 addresses ...
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0answers
11 views
What is the use of a host mask/ wildcard with respect to subnetting and ranges? [duplicate]
Taking the example of 10.0.0.0/20, that means my range is 10.0.0.0 to 10.0.15.255 I got that range because I know that the wild card is 0.0.15.255 and I just add it with the beginning address 10.0.0....
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1answer
112 views
Why does this ip address give me an error “must be valid ipv4 cidr”?
If I set up an AWS VPC with CIDR of 10.0.0.0/20 then the range is 10.0.0.0 to 10.0.15.255
I make a subnet now. Why does 10.0.15.15/28 give an error. Isn't it's range 10.0.15.15 to 10.0.15.30 which is ...
1
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0answers
17 views
Why did the IANA specifically choose these ranges for the the private IP address space? [closed]
10.0.0.0/8 IP addresses: 10.0.0.0 – 10.255.255.255
172.16.0.0/12 IP addresses: 172.16.0.0 – 172.31.255.255
192.168.0.0/16 IP addresses: 192.168.0.0 – 192.168.255.255
Is there any reason behind ...
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3answers
54 views
Routing IPs through another ASN
So currently we have a few /24 ranges that we are looking to use on an upcoming project, we also have an ip circuit with a tier-1 ISP and bgp peering is established.
Me and my business partner know ...
0
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1answer
104 views
Why DNS services Like google public DNS and Cloudflare 1.1.1.1 has ipv6 versions?
I understand the need for ipv6 as we ran out of ipv4 but dns resolvers like google and cloudflare already have ipv4 addresses for resolving dns and i don't see compatibility as a reason either because ...
1
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1answer
77 views
Ping to default gateway failing
I am trying to ping to a default gateway which i have configured as 171.2.0.1 but somehow the ping is failing . I am new to network domain so i have less idea about it . Any help is appreciated .This ...
0
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1answer
45 views
Need a little clarification with NAT and IPv6
I understand NAT exists to not exhaust all the ipv4 addresses so there is no need for it with ipv6. So with ipv6 having an unimaginable amount of addresses, will every device have its own public ...
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0answers
8 views
Confused in what maximum number of hosts and maximum number of subnets mean [duplicate]
Given a 172.12.0.0 /16 to be subnetted to appropriate networks. Branch 1 has 80 hosts, Branch 2 has 31 hosts and Branch 3 has 75 hosts.
I've already made a subnet table based on these using VLSM:
...
0
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1answer
37 views
Loopback interfaces subnets [closed]
Assuming that loopback interface is always alone in its network, what are the practical reasons to have IPv4 subnet prefix shorter than /32 for these interfaces?
Moreover, why according to various ...
2
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3answers
73 views
Routing with private addresses
Let's say that we have a private network, with private addresses and a NAT enabled router at the end. If the router is misconfigured and routes traffic to the global internet, keeping as source ...
1
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3answers
80 views
Combining NAT an tunneling
I was reading a text and a doubt came to mind. Suppose there is an interface in a router that implements NAT. That same interface is the extreme of a tunnel. If I was to send a message through said ...
1
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1answer
47 views
“SWIP” Equivalent for RIPE?
With ARIN, I was familiar with using "SWIP" for IP blocks via an ORG and a POC.
With RIPE, however, it seems that it's different.
I have access to a RIPE account where I can make the changes,...
2
votes
3answers
46 views
One client: static IP vs Static lease DHCP vs. DHCP limited range to 1 slot
I want to attach one client (only 1 maximum) to network router ethernet port. I want to always know the client's IP address, for my port forwarding settings. Using DHCP with range the client IP could ...
0
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2answers
60 views
Is the routing table used when sending IP packets to a host on the same LAN in ipv4?
I am having trouble understanding the steps in order to send an ip packet to another host on the same LAN. Most sources online that I have read and people I have talked to say that the host uses the ...
1
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1answer
33 views
By General Convention if we say the Frame size is 1KB do we take it as a 2^10 Bytes or 10^3 Bytes
In my academic we generally follow 2^10 Byte approach , I m really at loss is it by convention only at my college or something which is accepted widely
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2answers
428 views
Is not 192.168.88.1 (192.168.*.*) always an “internal” IP address?
I had some headache with a proxy setup which I couldn't figure out. Turns out that only "127.0.0.1" and "localhost" were recognized as "localhost" or "internal" ...
0
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1answer
1k views
How to find the first and last address in the FIRST AND LAST SUBNET [duplicate]
So there's a problem that literally stress me out every time I look at it. It's like I almost understand it until I get to knowing how to find the first and last host in the LAST address (last subnet)....
0
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1answer
31 views
Are there broadcast/collision domains on non-Ethernet networks?
What if we have routers or hosts connected via ATM, Frame Relay, or SONET; that is, what if we have IP over SONET, IP over ATM, IP over Frame Relay, etc., do we still have broadcast domains and ...
2
votes
1answer
92 views
IPv4 and UDP/TCP packets inside of ICMP packet?
A week ago, after opening wireshark, i was surprised by seing a storm of ICMP packets from different IP addresses. While deep analysing of thoses packets, i noticed that those ICMP packets contains ...
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1answer
44 views
IPv4 and IPv6 Source Address field
Both the IPv4 and IPv6 headers contain the source address field.
What are the reasons for including this field?
Is it for to trace which who sent this packet if it get's lost?
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0answers
12 views
How does the IPv4 Total Header Length field & Fragmentation work together? [duplicate]
I recently learnt that the maximum value of the IPv4 Total Header Length field is 65,535 which equals approx. 65.5KB. To my understanding, it is different from the IHL field as it includes the ...
0
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0answers
11 views
Why does sub-netting not give us more addresses? [duplicate]
Sorry if this is dumb, but I am very knew to learning about networks.
Here is my reasoning?
Let's take the address, 24.50.12.4
if we subnet it with /16 then the network address is 24.50 + host is 0.0....
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0answers
9 views
How to find Best Fit Mask [duplicate]
How does i find the best fit netmask (i.e., resulting in as few host addresses as possible) for a
network with 62 hosts in it?
I don't have any class like A,B,C
How can i find best fit netmask for ...
-1
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3answers
728 views
Confusion about TTL when pinging
TTL value of a packet is supposed to decrease 1 at each router from 255 down to zero as follows:
But when I ping to 8.8.8.8 the TTL starts at 253 and doesn't change:
How can this be explained? Why ...
0
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0answers
16 views
Is 12.23.34.45/24 a valid IPv4 subnet definition? [duplicate]
I believe the question says it all: when referring to an IPv4 subnet, is it valid to use 12.23.34.45/24?
If it is, is it equivalent to 12.23.34.0/24?
If it is not, can you refer me to helpful ...
2
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2answers
24 views
Understanding IPV4 address range [duplicate]
I do have basic understanding of IP Address which is unique address for each System either in an organization or over the internet. But i want to understand what is IP address range
Lets Say we have ...
7
votes
5answers
2k views
How does the shortage of IPv4 public IPs influence existing firewalls?
I came to know recently IPv4 public IP address pools are going to be exhausted soon. If IPv6 addresses are fully in use, all device vendors like Cisco, Fortinet, Palo Alto have to redesign their ...
0
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0answers
14 views
How does IP fragments assembled when identification number field is too small?
Please take reference from this question.
It is said in RFC 6864 that if IP V4 IDs remain unique during MDL, it would limit speed to max 6.4Mbps.
Now high speed devices generate data at a much higher ...
0
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1answer
26 views
Connecting to device which requires specific IP [closed]
[Disclaimer: I'm a complete networking novice, and this question might not even be well suited for this site. I welcome pointers to other stack exchanges if appropriate.]
I'm trying to connect a ...
0
votes
1answer
28 views
What are some techniques to infer the subnet being used? [closed]
Given a list of thousands of IPv4 addresses and that you have no direct access to these hosts, is there a service or a methodology to infer a subnet that's possibly being used?
0
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1answer
39 views
Understanding L2 Switch (Network Noob)
I currently have the setup on the left and it works just fine...
I use it to transfer data between laptop and embedded systems hardware device. (Data...Not internet)
Question:
What would the set up on ...
0
votes
1answer
27 views
TCP protocol mystery [closed]
I am attempting to compile, with pcap-filter, the following string:
host yb-in-f91.1e100.n
Obtained from the following command:
netstat -t
output line: tcp 0 0 os-info:portnum yb-in-f91.1e100.n
...
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2answers
61 views
Is the outgoing interface of a router in the same Subnet as the Incoming interface of the NEXT HOP router?
In the TCP/IP Volume 1, it is stated that ARP works only on the same subnet. Does this mean that the outgoing interface of a router is necessarily on the same subnet as the incoming interface of the ...
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2answers
31 views
What is the need for the NEXT HOP coloumn in the routing table when we already mention the OUTGOING INTERFACE in another coloumn?
If the OUTGOING INTERFACE is already mentioned in the routing table, it is natural that the next hop will necessarily be the router attached to the outgoing interface. Then why is there a separate ...
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1answer
94 views
different network mask and subnet mask and netmask [duplicate]
1- what is network mask?
2- what is subnet mask?
is there any differnt between network mask and subnet mask?
i'm tried to search about network mask and nothing found is it called netmask ?
thank you
0
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4answers
90 views
Private IP Address Subnetting Standards. How strict are they today? [duplicate]
How strict is this standard today.
The 172.16.0.0/12 range is: 172.16.0.0 – 172.31.255.255
Conceptual Config
172.Location.VLAN.Host
Location A (10):
VLAN 10 - 172.10.10.0/24
VLAN 20 - 172.10.20.0/...
0
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2answers
56 views
Possible typo in Tanenbaum's book about NAPT
From what I have understood from multiple sources (web and other books) about the concept of NAPT (also called NAT overload or IP masquerading in Linux environment), if there is a scenario like the ...
2
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1answer
74 views
what were the classless routing protocols used with VLSM when it was first introduced?
Since VSLM is supported only by classless routing protocols, if VSLM was introduced in 1987(RFC 1009) and all classless protocol(RIPv2 developed in 1993 , OSPF standardized in 1989 RFC 1131 ) cited ...
0
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2answers
396 views
Is TCP's MSL value equivalent to IP's TTL value?
Definition of MSL according to RFC 793:
Maximum Segment Lifetime, the time a TCP segment can exist in the internetwork system. Arbitrarily defined to be 2 minutes.
Definition of TTL according to ...
