Server Fault Stack Exchange
Server Fault Stack Exchange

Questions tagged [arp]

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.

421 questions
2
votes
0 answers

ipwatchd detects non-existing conflict?

Ipwatchd is telling me about a conflict that I just do not understand. As far as I can tell, there is no conflict. Am I reading the message wrong? It's a Xen machine with the following network interfaces: bridge 'eth0' (00:25:90:06:db:1c),…
Halfgaar
  • 8,084
  • 6
  • 45
  • 86
2
votes
0 answers

Can ARP with IP aliases on Windows be made to behave like on Unix?

On FreeBSD, when I have one interface with two IPs: ifconfig nic0 192.168.0.1 netmask 255.255.255.0 ifconfig nic0 alias 192.168.0.2 netmask 255.255.255.255 If I ping the alias, if the host I'm pinging from, e.g. 192.168.0.20, is not yet in the ARP…
Thijs van Dien
  • 141
  • 5
2
votes
1 answer

Which are the possible reasons for an arp request that is not being solved/answered?

This weekend I was testing a new data link connection from a service provider, and I went through some address resolutions problems. I tested reachability to hosts at the far end using a laptop on my side with some network parameters provided by the…
Jorge V.
  • 292
  • 1
  • 4
  • 12
2
votes
3 answers

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 where machines can be added or removed by…
Ido
  • 21
  • 1
  • 3
2
votes
2 answers

arp packet received larger than packet sent, why?

I'm trying to debug a networking issue. During this process, I've noticed that when I try to do an arping, the received arp packets are larger than sent arp packets, as outputted by tcpdump. (Note that both ends have a br100 bridge to the eth1…
Lorin Hochstein
  • 5,028
  • 15
  • 56
  • 72
2
votes
1 answer

Can arping by IP but not MAC address

I have an interface that I can arping to by its IP, but not its MAC address: # arping -i eth2 10.10.0.153 ARPING 10.10.0.153 60 bytes from 02:68:b3:29:da:98 (10.10.0.153): index=0 time=81.062 usec 60 bytes from 02:68:b3:29:da:98 (10.10.0.153):…
Lorin Hochstein
  • 5,028
  • 15
  • 56
  • 72
2
votes
1 answer

Cisco ARP table: determine directly connected devices

I have a Cisco switch and a big list of servers on the network. I need to determine what servers are connected directly to that switch. Will searching for the MAC address of each server in the switch's arp table (show ip arp) assure me that the…
Megaslav
  • 117
  • 1
  • 5
  • 9
2
votes
1 answer

Windows server sending constant ARP requests to offline devices

We have a Windows 2003r2 server which is sending intermittent ARP requests to several devices which are no longer on the network. The result of this is disruption to a PLC which is running over modbus. The server runs DHCP, Print Services and File…
user1693454
  • 135
  • 1
  • 3
  • 11
2
votes
1 answer

Solaris Slow ARP Failure Unreachable Host

We have been experiencing slow timeouts for unreachable hosts is extremely slow. Recent testing in our lab shows it may be a delay reporting negative ARP lookups. Dumping traffic during attempts to open a telnet connection to a local zone which…
BillThor
  • 27,737
  • 3
  • 37
  • 69
2
votes
2 answers

Failure to obtain IP with ARP over Wi-Fi with personal Wi-Fi router in client mode

I'm trying to connect a Samsung TV to the Internet using a TL-MR3020 personal wireless router in client mode. The TV fails to connect to the network. It sees the ethernet cable connected though. Here's my network topology: Here's what I've captured…
axk
  • 267
  • 1
  • 6
  • 14
2
votes
2 answers

pfSense 1.2.3 can't talk ARP beyond a switch two hops away

I have the following devices on vlan93 on my network: pfsense (192.168.93.1) core-sw1 (192.168.93.2) edge-sw1 (192.168.93.3) pf-switch (192.168.93.100) devices (192.168.93.120) Physical connections below (all connections are tagged except for…
MikeyB
  • 39,291
  • 10
  • 105
  • 189
2
votes
2 answers

Will a host accept any ARP response it gets and updates its cache

I am trying to understand ARP and ARP cache poisoning. Will a host updates its cache if it gets an ARP response even if it didnt send a request? If yes, is there any particular reason it is designed like that? Also I have one more question. In case…
user1004985
  • 125
  • 4
2
votes
2 answers

Why computer scanning network?

I have found out through Wireshark that a computer in my subnet scanning network ( sending ARPs for every IP-address in my subnet. Even if there no computers with such address). It repeats infinitely. About 200 ARPs per sec from this computer. …
Temak
  • 195
  • 1
  • 3
  • 11
2
votes
5 answers

Extremely high arp flooding from the router

My subnet is 10.162.0.0/16. We have a router with a couple of interfaces. Our gateway address for this subnet is 10.162.0.1. The router is in another building and I haven't got direct access to it. Line from router comes to my main layer-2 switch…
Temak
  • 195
  • 1
  • 3
  • 11
2
votes
5 answers

Cisco WS-C6509-E Arp Cache Corruption Issue?

We are having an issue with our Catalyst 6500 switch where we suspect that the ARP cache is being corrupted. This presents itself with the following symptoms: When you attempt to ping a system which has not been resolved before, the first ping…
esac
  • 261
  • 2
  • 8
  • 12
1 2 3
…
28 29