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.

learn more… | top users | synonyms

2
votes
1answer
28 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 ...
-2
votes
1answer
20 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 ...
2
votes
3answers
54 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 ...
2
votes
2answers
39 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
votes
1answer
16 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)
0
votes
2answers
27 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 ...
0
votes
0answers
27 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 ...
0
votes
1answer
22 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 ...
0
votes
2answers
38 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 ...
0
votes
0answers
18 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 ...
0
votes
0answers
21 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 ...
3
votes
1answer
71 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 ...
0
votes
1answer
110 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 ...
0
votes
4answers
69 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 ...
-3
votes
1answer
62 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
0
votes
0answers
207 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
votes
0answers
38 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
vote
1answer
78 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 ...
1
vote
2answers
424 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 ...
0
votes
0answers
113 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 ...
1
vote
0answers
88 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 ...
1
vote
2answers
262 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 ...
0
votes
1answer
250 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 ...
0
votes
1answer
57 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 ...
-4
votes
1answer
325 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 ...
0
votes
2answers
106 views

Why am I not getting an ARP reply with this request?

Using pcap_sendpacket in C, I'm manually sending the following packet on wlan0 (I've left out some fields, but I think they are correct): (Ethernet layer) eth src: <wlan0 MAC address> eth ...
0
votes
0answers
32 views

How to meet the arp table and the network toology with wireshark

I'm wondering if is possible meet(see) the arp table in a network traffic with wireshark or find some way to build manually the arp table, and how to see the router and swiches of topology( for ...
1
vote
0answers
151 views

Broadcom NICs, Cisco ASA and ARP request collisions

First of all I am sorry for my english mistakes. Help me please to solve the problem with ARP request collision incidents. I have IBM BladeCenter E chasis with blade servers are installed in this ...
0
votes
0answers
64 views

FreeBSD jail loses network connectivity after some time

I have a Jail on a FreeBSD 9.2 installation on my office network, which I use to run some cron jobs that upload and download stuff from external servers. The cron jobs are configured on the main ...
0
votes
0answers
106 views

Pinging two virtual interfaces(IP aliasing) not working

I have two VMs. I have created a virtual interface on each of the VMs. On VM1: eth0 Link encap:Ethernet HWaddr 06:98:82:00:00:39 inet addr:10.129.34.76 Bcast:10.129.255.255 ...
0
votes
2answers
245 views

External ip address being treated as local (ARP asking for external IP's address)

I am using a virtual machine with OpenWRT for routing, on a Linux machine (Slackware). I am trying to configure a host only interface (eth0) as the wan interface. eth1 is Ethernet attached as a bridge ...
0
votes
1answer
104 views

How can I tell what's happening to my packets?

I'm trying to bring up a little box on my network. I just reflashed the firmware and it's supposed to come up as 192.168.1.1 by default. My router is a DSL modem at 192.168.0.1; it usually uses a ...
0
votes
0answers
319 views

VMWare use of Gratuitous ARP REPLY

I have an ESXi cluster that hosts several Windows Server VMs and around 30 Windows workstation VMs. Packet captures show a high number of ARP replies of the form: -sender_ip: VM IP -sender_mac: VM ...
0
votes
0answers
52 views

How to fix stalled connection on large download

I have a cisco 1921 router performing routing and NAT function. Cisco 3750 is performing layer 3 core switching duties. Users are complaining about large file transfers being stalled (not dropped) ...
0
votes
2answers
185 views

Windows 8 is not always selecting correct network card for my outgoing transmissions

The company I work for builds and sells industrial machines. One of our products is a machine which is controlled by a PC running Windows. This particular machine uses a networked device with ...
0
votes
0answers
102 views

X520-DA2 10GbE PCIe NIC on Ubuntu 12.04 doesn't respond correct ARP information for a traffic tester

I'm trying to configure stand-alone test network to examine a server that has two 10GbE ports PCIe NIC. But I couldn't get any ARP responses of those 10GbE ports. To execute my test, it's necessary to ...
1
vote
1answer
182 views

Directed ARP requests do not arrive at bridge interface

I'm baffled by the following weird bridge/arp behavior under Linux. It somehow seems to filter directed ARP requests, whereas it should forward them to the other end of the bridge. To test, I run the ...
0
votes
0answers
33 views

SYN-ACK with identical MACs

What could cause a CentOS machine to respond with SYN-ACK packet having both source and destination MACs set to the address of the NIC from which the packet is being sent?
0
votes
1answer
200 views

Group Policy for Time Sync = ARP Flood?

I have a Windows Server 2008 R2 domain controller and a bunch of workstations of various versions of Windows - XP SP3, Vista, 7, 8.1. Time sync wasn't working correctly on a few PCs so I followed the ...
0
votes
0answers
57 views

Strange network issue when moving EC2 elastic IP

Recently we had an issue with a Windows 2012 EC2 server, which meant that we had to move across to another instance. We duplicated the instance, ran some tests and moved over the elastic IP. Should ...
1
vote
1answer
734 views

arp problems with transparent bridge on linux

I've been trying to secure my virtual machines on my esx server by putting them behind a transparent bridge with 2 interfaces, one in front, one at the back. My intention is to put all the firewall ...
0
votes
2answers
167 views

Must an ARP broadcast query packet contain the target node's MAC address [closed]

So far as I know, Address Resolution Protocol (ARP), translates the IP address of a computer on a local network to an equivalent layer 2 address (MAC address), such as sending a packet from machine A ...
2
votes
1answer
357 views

Determine the hostnames of IP conflict

I have a network with several hundred machines on it. I have a machine that gives intermittent connectivity issues, reported via vSphere web client. This troublesome machine has the hostname ...
0
votes
3answers
217 views

Linux (Ubuntu 12.04) sending ARP requests over single interface

I have a system with custom hardware hooked up to 2 different ethernet ports on the same system. The interfaces are configured on the same subnet because the hardware (FPGA-based) has a hardcoded IP ...
0
votes
0answers
130 views

localhost answering wrong ip

No idea how/why, but here's what I'm seeing. Consider 3 CentOS 5.10 boxes: Host A [10.1.2.7] Host B [10.1.2.8] Host C [10.1.2.9] All of a sudden we're getting strange behavior from Host X, ...
-2
votes
3answers
75 views

Prevent Linux server host from using ARP

If I know all client will connect to the sever with the same MAC address and to the same interface, is it possible to prevent from server host to send ARP request for each new client IP it gets a ...
3
votes
1answer
155 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 ...
1
vote
1answer
411 views

“Destination Host Unreachable” and ARP returns no addresses over LAN

I am currently trying to setup LAN over two machines with a network mask of 255.255.255.0 however I am receiving the following message when trying to communicate between them both; [root@alpha ~]# ...
2
votes
1answer
231 views

network level of veth doesn't respond to arp

I decided to play with veth : create a veth pair and send a ping from one end to another. $ ip link add type veth $ ip addr add 192.168.99.1 dev veth4 $ ip addr add 192.168.99.2 dev veth5 $ ip link ...
1
vote
3answers
697 views

Switch behavior on unicast packets when the destination is unknown

Please let me start by saying I am no network expert, I am a programmer who does a fair amount of L3/4 programming. My question is that when a switch receives a packet with a destination MAC that is ...