Address Resolution Protocol is a layer 2 networking protocol used for resolving layer 3 addresses (such as IP addresses) into layer 2 addresses (such as Ethernet MACs). It is used by network devices when communicating with devices on the same layer 2 network.

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Ping is happening but arp is not resolved

I am seeing one interesting problem. I have setup two devices connected through lan cable over eth3 interface. Now a vlan session has been created on both the interfaces. Device 2: root@10:~ ...
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3answers
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arp --detete is not deleting an entry; merely marks entry as “incomplete”

I run arp --delete and it leaves the entry but it's simply marked as incomplete. I expected --delete to entirely remove the entry. Does anyone understand what is occurring here? $ sudo arp -avn ? ...
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1answer
28 views

Why ARP cache is not emptied as I except it to be?

I'm trying to empirically test the time an entry stays in the ARP cache table. This time seems to be defined by /proc/sys/net/ipv4/neigh/default/gc_stale_time file and by ...
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5 views

arptables arp filtering with openvpn tap interface

I want to prevent arp traffic not coming from my default gateway going through a openvpn tunnel. Server Setup: /etc/network/interfaces auto br0 iface br0 inet static address AAA.AAA.AAA.AAA ...
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2answers
30 views

Arp request for a non-existing host in a local network

I'm wondering why I get the following result : if I try to access a non-existing host on my local network, for instance using the command ping, I see with the tcpdump arp command that there is every ...
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Can not delete properly ARP Table

I have the feeling that I can not delete completely my ARP table on my Mac with the last OS Yosemite. Here is what I do : Device A with IP "IP-A" is connected to the LAN with wifi I ping "IP-A" I ...
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97 views

What causes the Linux neighbour table confirmation counter to be reset

Given three linux hosts on the same broadcast domain, the sender constantly pings an IP bound to receiver1. When moving the IP address from receiver1 to receiver2 it takes a quite long time for the ...
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1answer
49 views

Broadcast ARP query to all nodes?

I am trying to broadcast an ARP query. I want to get every node's ip and mac address updated in my system via this query. So that I can type $arp and see all the nodes on my network and their ...
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2answers
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ARP reply vanishes from br0 to tap0 using OpenVPN in bridging mode

I have setup a linux box (on an esxi5) which acts as an OpenVPN server. the server is configured to use bridging for the clients, which essentially works, with one exception. If the client pings some ...
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13 views

Wireless devices see ARP replies but not requests, monitor interfaces see both

For the sake of brevity, let's call the wireless interface used for access point (AP) to device communication "wlan0" and the interface used for sniffing in monitor mode "wlan1." In my case, wlan1 is ...
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27 views

Two arp responses mysteriously show on IOS 8.3 [closed]

Here's my problem, maybe you can shed light on this, any help is appreciated more than you will ever know. I've been being targeted for a few years now and am having this ARP problem on my iPad Mini ...
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4answers
182 views

How to find all hostnames (even laptops that aren't currently on the network) on a network?

I manage a network that has a lot of laptops. The users that use the laptops are frequently traveling. When someone gets a new computer I run into a problem determining what the hostname should be. ...
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2answers
53 views

ARP packets are sent as IPv4 packet [closed]

Is it true and why? ARP packets are sent as IPv4 packet. Thanks, in advance.
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1answer
50 views

IPv6: I'm confused about addresses [closed]

I'm starting studying IPv6 and I'm having some troubles understanding some aspects. Let's clarify if I'm getting this right! A single host may have: - a unicast global address - a link local address ...
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0answers
34 views

MAC address in arp table doesn't match actual MAC, why?

If I connect my laptop directly to the config port of a ubnt airFiber radio I can set a static IP to my laptop and access the default config page to change settings on the radio. When I look at the ...
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1answer
2k views

How to setup a static multicast ARP entry with Cisco SG300?

We're running a Microsoft NLB cluster in multicast mode as a loadbalancer. Using our old Cisco IOS switches we propagate access to the cluster to our branches using a static ARP entry in the core ...
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1answer
46 views

Polycom VOIP phone seems to mask the secondary device's MAC address from a Cisco switch

When I have a Polycom VOIP phone plugged into a Cisco switch and a laptop plugged into the Polycom phone I get the following. 1) The phone goes into the voice VLAN as expected. 2) The laptop goes ...
2
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1answer
85 views

Windows 8.1 Limited Connectivity (on Steroids)

About two weeks ago we performed maintenance on our on-premise infrastructure in our office. Including applying updates to our Hyper-V-based virtual hosts, as well as our SAN. We also modified some ...
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1answer
35 views

Why is there flooding on L2 but not on L3?

Why is it, that on L2 (when there is no MAC Table entry for a new packet) there is MAC Flooding. But at the same time on L3 there is an ARP request (when there is no entry in the ARP table for a new ...
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3answers
84 views

Scanning network devices by mac address

I work in the security devices industry and most of my work relates to IP cameras. Each camera manufacturer has their own software that scans the network for their cameras and gives details about ...
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1answer
88 views

Can you SNMP poll the ARP table on Cisco ACE?

I'm trying to get a MAC <=> IP mapping from a Cisco ACE. Unfortunately according to this table, while it supports IP-MIB the ipNetToMediaTable and ipNetToPhysicalTable subtrees are not supported. ...
2
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2answers
63 views

New server unreachable for a time after swapping IP address

I am migrating nearly 20 websites from a win 2003 server to a win 2012 server. Both are VMware VM's, on different boxes, but in the same server room, and attached to the same switch. The 2003 server ...
3
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1answer
31 views

Default arp cache timeout

I didn't found how check and change the default arp cache timeout on Linux. I using debian with kernel 3.x (but I supposed it same with older kernels)
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2answers
53 views

arp table entry outside configured network

Can someone tell me why do I have arp table entry outside interface network? Server has 2 interfaces, both on the same network: eth0 10.10.34.146/22 eth1 10.10.33.188/22 ip route default via ...
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4answers
4k views

Persistent static ARP entries on Windows, is it possible?

I am currently running coLinux configured in "ndis-bridged" networking mode, on a machine whose wireless networking card or driver seems incapable or unwilling to accept non-broadcast layer 2 traffic, ...
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0answers
73 views

ARP/ICMP in a network environment with overlapping IP address

Currently I have lab network setup to mimic customer's network deployment. (According to the customer, they are using VRF over VLAN so that their customer can have overlapping network connecting to ...
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8answers
69k views

Is there any way to ARP ping on Windows?

On Linux and other systems, there is an utility called arping which can be used to send ARP requests ("pings") and show the answers, much like the "ping" utility but using ARP instead of ICMP. Is ...
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1answer
32 views

Master and slave devices talking to each other through another device with two interfaces. All in the same network

I have three devices, one is a master which will talk with the slave and Device3 but it is only physically connected to the Device3. The slave will speak only with the master(also through the ...
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2answers
60 views

Is turning off ARP a common practice?

I'm just trying to diagnose a problem I and a colleague have had on two separate occasions to swap out an old router with a new one. Both starting from scratch, we've found that we can't seem to ...
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1answer
1k views

How are ARP reply collisions typically handled?

If a node receives multiple, conflicting ARP replies, what happens?
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0answers
29 views

Broadcast ARP weirdness

we a running a router on a custom Linux box. Kernel is 3.14.14. What happens is that when you arping the router in broadcast only mode is the router has a verey slow response time: # arping -b -c ...
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2answers
897 views

Arp requests with odd source IP go unanswered

I'm having a server with network connectivity issues that I presume come from issues with arp protocol handling. Let's say the network topology is as follows: network 192.168.106.0, netmask ...
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1answer
97 views

Is it the normal behavior of arp requests?

Sometimes I dive into my network and often I see: tcpdump -n arp 17:59:15.754508 ARP, Request who-has 192.168.1.65 tell 192.168.1.212, length 28 17:59:16.754401 ARP, Request who-has 192.168.1.65 ...
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1answer
381 views

Cisco ASA 5510 needs “clear arp <Interface>” periodically to reach a single host

ASA 9.0(3) The symptom is that I can ping from the ASA to any other host in that interface's subnet, save one particular host (that host can ping the interface on the ASA however). If I do "clear arp ...
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1answer
494 views

How to reverse arp using nping for Windows

I would like to send a reverse ARP to resolve an IP address given a MAC address using nping for Windows. The documentation is not clear on how this should work and I'm unable to find any examples ...
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6answers
19k views

Is it possible to match an internal IP address to a switch port?

I'm trying to find a computer that has a certain IP address on our internal network. I have identified the computer name from DNS, but in this case it does not help me. Just wondering if I can ...
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1answer
75 views

First Reply on Ping is Unreachable the rest is okay [closed]

please check this weird ping i'm having What may have caused this problem
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1answer
181 views

VMXNET3 nic loses the ability to update ARP table after N hours

I have a fedora 18 VM that stops updating the arp table on eth1 after running for a number of hours to days. There are other VMs on the same hypervisor that can access all of the same networks without ...
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4answers
76 views

Fault tolerance by using two IP with two interfaces

I would like to have a fault-tolerant setup for http requests. For brevity, let's assume we have a very simple Web-service and there is no difference which server responses. So I will have the ...
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0answers
265 views

KVM Windows guest macvtap host device bridge no access to network but DHCP works

KVM on CentOS 7, guest OS windows 7 x64, I need the guest to have direct access to network and let my network infrastructure to handle IP addressing. In virt-manager, I set NIC to: source device => ...
2
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0answers
50 views

arp poisoning and mitm protection [closed]

I'm trying to understand mitm by arp poisoning. To do so I'm practicing on the network I manage: attacker : IPA victim : IPC gateway : IPG I use nighthawk, and kali linux (via virtual box). I can ...
1
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1answer
181 views

How to troubleshoot internet unreachable periodically through firewall

Periodically the internet is unreachable on my network, sometimes for 30+ minutes. After testing a direct connection to our modem, I realized this was not a problem with our ISP but the network ...
9
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6answers
10k views

ARP replies contain wrong MAC address

I've got a robot running linux with wired and wireless adapters. When I boot up, it connects to the wireless fine. When I assign an IP to the wired (either statically or with DHCP), it looks like it ...
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2answers
720 views

Linux is sending ARP requests to hosts in other subnets?

Setup Host B <--> Router <--> Host A Host A: IP = 192.168.1.10, Net = 192.168.1.0/24, VLAN = 1, Default GW = 192.168.1.1 (Router) Host B: IP = 192.168.2.10, Net = 192.168.2.0/24, VLAN ...
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3answers
2k views

Linux machine does not answer an ARP request

We have this situation: A router, which is an Ubuntu VM, has multiple VLAN interfaces on the same physical NIC. Those VLAN interfaces are dynamically configured and torn down and attached to networks ...
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0answers
140 views

Linux bridge not answering arp packets

I'm trying to setup a test scenario regarding linux bridges for which I need a full virtual IP stack. Basically, I'd like to simulate the network between a VM (or container) and its host, just without ...
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0answers
120 views

linux not replying to an arp request

I am running linux 3.14 on a system with 2 interfaces. on the first interface, i can access our local network. on the second interface, arp packets come in but linux doesn't send out reply. is it ...
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2answers
277 views

How is a TCP request routed from a virtual machine to an outside resource and back again?

Scenario: Computer A has a local ip of 192.168.1.100, which is running a VM inside of it. The VM now makes a tcp request to an external IP address (74.125.225.98). Could someone explain how the ...
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1answer
65 views

iptables: service per physical interface

I have a vm on which I'm trying to configure (unsuccessfully) one service per physical device - i.e. ssh open only on eth0, http only on eth1 and ftp only on eth2. This has to happen regardless on the ...
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1answer
590 views

How does Bind IP to MAC work? [closed]

A client is connected to the network with a DHCP server, but also has a Bind IP to MAC entry in the router. What is the sequence of steps that determine the final client IP configuration given that ...