ARP (Address Resolution Protocol) is a protocol used to find an address from the link layer (Ethernet, for example) from the network layer address (such as an IP address).
Questions tagged [arp]
281 questions
70
votes
2 answers
What is the difference between ARP binding and DHCP address reservation?
In my TL-WR1043ND I have these functionalities and both of them pair an IP address to a MAC address. What is the difference?
I read that ARP is for security reasons, others say it is for Wake-on-LAN. I also read there is no difference, but in that…
totymedli
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55
votes
3 answers
Why is ARP replaced by NDP in IPv6?
ARP was replaced by the NDP (Neighbour Discovery Protocol). But I don't know the exact reason for this.
Are there any security issues in ARP?
Why ARP is replaced by NDP?
What are the advantages of ARP?
Can anyone explain this in simple terms?
Ganeshgm7
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35
votes
2 answers
Windows 7: The ARP entry addition failed: Access is denied
I'm on Windows 7 and am trying to assign a static arp entry for my default gateway using the command:
arp -s 172.24.7.254 00-05-01-f9-28-00 172.24.1.20
But I get the following error:
The ARP entry addition failed: Access is denied.
When I don't…
0fnt
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30
votes
2 answers
Does the order of entries in the routing table matter?
Does the routing order matter:
> route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
123.x.x.151 0.0.0.0 255.255.255.255 UH 0 0 0 vmbr0
123.x.x.154 0.0.0.0 …
static
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26
votes
5 answers
how does 'ping' command really work?
How does the ping command really work? Specifically where does the ARP (Address Resolution Protocol) come into picture?
I was asked this question in an interview and I was not able to come up with a scenario when ARP could be used.
liv2hak
- 596
23
votes
1 answer
Where is the ARP cache on Linux?
Where, in memory, does the ARP cache exist? I tried searching it up online but didn't find anything.
ssharma
- 353
20
votes
3 answers
what's IPv6 analogue for IPv4 `arp -an` and "arp who-has"?
In the IPv4 world, when you want to talk to another computer, you ask which MAC address claims a given IPv4 address, the arp who-has ... tell ... exchange as per tcpdump, and a cache of such mappings from IPv4 to MAC addresses is usually available…
cnst
- 2,615
19
votes
3 answers
What is the I.P. address 224.0.0.22 for?
Possible Duplicate:
What are the purposes of the addresses in this ARP table?
I notice that ANY computer that I go to, if I do a arp -a command from a command line, I receive a reply back of 224.0.0.22. It returns as a physical address and is…
C-dizzle
- 1,946
12
votes
3 answers
arp requesting to another subnet, how?
I’m wondering if I have a computer in subnet A with IP address 192.168.123.1, and a computer with IP address 192.168.124.1 in a different subnet.
Both networks are connected with a router. If I want now to send a packet from computer A to computer…
user3673517
- 135
10
votes
2 answers
How to get device name from scan like nmap on Linux
I know that I can use a tool like NMAP or arp-scan on Linux to identify the IP and MAC addresses of all devices on my local network. I also know that arp-scan will do a MAC address lookup to get the device manufacturer. But is there any set of…
Marc
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10
votes
6 answers
Why do we need IP addresses to communicate within the local network segment?
Because MAC addresses are only usable across the local network segment, we use IP addresses to communicate with other segments via routers. Meanwhile, for local targets, ARP is used to translate IPs into MAC addresses and the MAC addresses are used…
Sufiyan Ghori
- 432
7
votes
2 answers
How to set up a static/persistent ARP entry with OpenWRT 14.07, Barrier Breaker?
The title say it all, but here is the long version:
I am trying to setup a way for my home server to automatically turn on using WakeOnLan, when a client tries to access it. My idea is that the router (OpenWRT 14.07, Barrier Breaker) monitors any…
packoman
- 213
7
votes
3 answers
Detect IP Conflicts on Network
I have a Wireless WAN network that I am managing devices on. We recently had an IP conflict that took us over 10 months to find (we had no idea there was even a conflict until we were pinging a device and pulled the plug and it kept pinging). Are…
TheFrack
- 289
7
votes
3 answers
Given a PC's MAC address, can I find its IP?
Is there a way to get the IP address when all you have is the MAC of an item?
IT_07
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6
votes
4 answers
How to run webcam software only when I am not home (phone is not on the LAN)?
Currently I've got my user cron starting Motion on a timer when I typically leave for work, and then killing it when I typically get home, so I can watch my cat/burglars/etc:
0 9 * * * killall motion ; motion
30 18 * * * killall motion
The config…
endolith
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