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.
125
questions with no upvoted or accepted answers
1
vote
2
answers
3k
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 ...
1
vote
0
answers
795
views
Duplicate entries in switch ARP table
A server is showing twice or more on my L2 switch ARP table
Same IP address, mac address, and ethernet port.
What could be causing this?
Thanks
1
vote
1
answer
152
views
Understanding ARP traces during OS load
Consider the following ARP packets captured while a unix machine was booting.
From the packets I understand that this machine whose MAC address is 00:22:22:22:22:22 is requesting information about ...
1
vote
0
answers
943
views
ARP Tables on Windows vs Linux
I noticed on Windows Server 2008, Windows Server 2008 R2, and Windows 7 that IP multicast groups joined by a computer are recorded in the ARP table as static addresses automatically. However, the same ...
1
vote
1
answer
214
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. ...
1
vote
0
answers
720
views
Keepalived, Junos, and ARP caching
I'm trying to configure an active-passive stunnel setup, with the aid of Keepalived, for a public IP address at our company datacenter. I would like to know if a router or switch reconfiguration is ...
1
vote
0
answers
2k
views
arp reply is not processed
My eth0 interface does not process a legitimate arp reply.
When I try to ping a host, I see arp request and reply with tcpdump from the host I try to ping from, but ip neigh says that there is a ...
1
vote
0
answers
1k
views
Cannot ping any machine on local network (embedded linux device)
I have an embedded linux installation (custom built using buildroot, uClibc and busybox) and I am unable to ping any machine on my local network. My /etc/network/interfaces file is as follows
auto lo
...
1
vote
1
answer
797
views
openvpn connects but does not work until server pings client
I'm trying to configure a connection using openvpn from a windows 7 client machine to a linux host. I'm using openvpn in the traditional routed mode using tap devices, and the configuration I'm using ...
1
vote
0
answers
381
views
What is the meaning of the QUEUE in arptables
I use the nfqueue target of iptables in order to get packet to the nfqueue and do some business rules on them.
iptables -A INPUT -p tcp -j NFQUEUE --queue-num 0
I need to do the same on arp reply ...
1
vote
0
answers
3k
views
Arp request is not resolved
On my machine, I have assigned ip addresses for two interfaces which are connected through a cable. They are connected with 10G ports.
When i tried to ping the two addresses, ping was not working. ...
1
vote
0
answers
84
views
Server Core DNS Server in VSphere doesn't respond to ping and needs continuous arp clean
I have a VSphere installation hosting two Windows Server 2008 R2 installations. One of them is a complete install that serves as a DHCP server and that I use for administration. The other install is a ...
1
vote
1
answer
1k
views
Proxy arp and 1:1 NAT
I have a Linux router with 2 NICs doing masquerade from network 192.168.0.0/24 to an ADSL router.
users <----> NIC A [router] NIC B <----> INTERNET
Now I'm experimenting with proxy arp ...
1
vote
0
answers
416
views
virtualbox bridged adaptor works only guest->host but not host->guest
I have virtualbox 4.1 on a ubuntu 12.04 host. On my host I have a virtual interface eth0:1 configurend as 10.0.1.1. I have a few virtual machines using bridged adapters, configured in the 10.0.1.0 net ...
1
vote
0
answers
427
views
Windows Server 2003 DC sends Gratuitous ARP requests with wrong IP
Hello and excuse me for my English please. ;-)
Two server seems to be involved with this problem. Our DC (domain controller, 2003) an the VMware VC-Server (2008 R2).
After capture "some" network ...
0
votes
1
answer
93
views
No connectivity in LAN (arp table does not learn IP addresses)
enter image description hereI have a server connected with NICs as follows,
10.0.11.11/24 - no gateway required.
10.0.10.11/24 - with gateway 10.0.10.240
192.168.2.11/24 - no gateway required.
When ...
0
votes
0
answers
90
views
S2S VPN - cannot ping B from A until A pings B
I'm working on site-to-site VPN between 2 networks within private cloud. On both ends I installed Strongswan and established VPN connection.
The problem is that I'm not able to ping from A (10.0.1.0/...
0
votes
1
answer
186
views
Ping: "Destination Host Unreachable" even though ARP request succeeds
I have a wired interface with a static IP configured. Pinging the gateway results in "Destination Host Unreachable".
PING 10.3.3.246 (10.3.3.246) 56(84) bytes of data.
From 10.3.3.8 icmp_seq=...
0
votes
0
answers
85
views
Martian packet with ARP broadcast traffic
Server nodes keep getting ARP broadcast traffic and becoming martian packets due to assymatric routing. I was known that when strict filtering is enabled with net.ipv4.conf.eth0.rp_filter = 1, the ...
0
votes
0
answers
48
views
Redirect Traffic on OVS switch
I have below topology on mininet:
Host1:10.0.0.1/24 mac :aa:00:00:00:00:01
Host2:10.0.0.2/24 mac :aa:00:00:00:00:02
Host3:10.0.0.3/24 mac :aa:00:00:00:00:03
I want to redirect traffic as below:
When ...
0
votes
1
answer
291
views
MITM attacks inside VPN network?
Is it possible to use any MITM attacks (including ssh-mitm) if I'm connected to a VPN? OpenVPN connects me via tun0 interface with some IP in 10.0.0.0/8 and gateway at some IP 10.0.0.0/8. I know that ...
0
votes
0
answers
108
views
Ping request generates response but sender doesn't see response
I have an embedded linux system with an ethernet PHY that is connected to a switch and then directly to my PC. After setting static IP addresses I found I could not get a working ping in either ...
0
votes
0
answers
71
views
Is there a method of performing "local arp" requests on linux
I have some code that performs an arp-scan, I wondered if there was a way within a single machine to have "something" respond to arp-scan within the same host.
I've tried a few things so far ...
0
votes
1
answer
60
views
Using a VLAN in embedded linux and although a response is received no entry made in ARP table
I need to set up 2 VLANs, but I have this issue even with only one configured (.2) but when I set up the other VLANc (.1) it seems to work ok.
The issue is that ARP doesnt seem to work which sort of ...
0
votes
0
answers
426
views
ARP Cache Entries Invalidated
I am doing some SDN research. In order to avoid having to route ARP packets, I manually set arp IP to MAC mappings on the hosts using the arp -s <ip> <mac> command.
Link failures are ...
0
votes
0
answers
92
views
Linux MAC learning outside network
How can I forbid create ARP records in Debian for IP outside network assigned for device?
For example:
ip route
10.10.0.0/20 dev ens4f1.10 proto kernel scope link src 10.10.0.1
10.11.0.0/22 dev ens4f1....
0
votes
0
answers
250
views
ARP Weirdness - Missing ARP replies?
Here's a picture of the relevant portion of my network.
The problem is as follows:
The Windows PC at left and the Synology NAS are both able to reach the two webcams (ping) and the ARP tables on ...
0
votes
0
answers
2k
views
ARP Reply is not forwarded to TAP device through Linux Bridge
Create two TAP devices, each of which will be read and written by the userland protocol stack. In addition, the two TAP devices are bridged by the Linux Bridge.
The script to prepare the environment ...
0
votes
0
answers
101
views
ARP Connectivity Issues Between OpenMediaVault Server and BSD Jails
On my network I have two servers.
Server1 is running TrueNas(BSD) with multiple applications running in iocage jails. It's connected to the network with a 3-nic LAGG.
Server2 is an OpenMediaVault (...
0
votes
1
answer
511
views
Limit ARP to gateway IP only
My current network setup is as follows
auto lo
iface lo inet loopback
dns-nameservers 8.8.8.8 8.8.4.4
auto eth0
iface eth0 inet static
address 104.244.72.242/32
gateway 107.189.30.113
pointopoint ...
0
votes
0
answers
2k
views
Linux does not send arp reply
I have an interface keeping receiving arp request but never respond. Can anyone help?
My interface ip is 192.168.40.2.
The routing table looks good.
0
votes
0
answers
638
views
rsync broken pipe between two servers on different networks
I have two FreeBSD servers, both on different networks, with a firewall in between. I have no control over the firewall.
Server 1:
IP: 10.1.0.2
GW (firewall): 10.1.0.1
Server2:
IP: ...
0
votes
0
answers
350
views
How do l manually set an arp table entry to reach an otherwise unreachable host in debian
I'm trying to reach a host on an internal network whose configuration has gotten screwed up, and isn't pulling a DHCP lease as would be expected. I have a host on that network that l'm trying to use ...
0
votes
0
answers
309
views
arping not working in docker
I'm currently trying to add a presence feature in my OpenHab installation by detecting presence of our mobile phones. For iPhone an arping is necessary, unfortunately it looks to me like arping won't ...
0
votes
0
answers
81
views
Debian / Kerio is ARP storming my ISP after loosing connection to the gateway
The problem: after Kerio Control (Debian) lost connection to the gateway it starts sending ARP like for "who has 8.8.8.8?" in such frequency, that the gateway gets shut down due to packet inspection ...
0
votes
0
answers
588
views
Behavior of ARP when using VPN bridge
I'm experiencing trouble connecting infrastructure using VPN. i don't have lots of rights with the VM i'm using so it's hard to give you précision, so this topic should be theoretical.
There is 3 ...
0
votes
1
answer
365
views
Manually building an ARP table
I am using a real time operating system called Vxworks 5.5. The address resolution protocol is disabled and now I need to build up an ARP table manually to initiate IP to IP communication. The IP ...
0
votes
1
answer
2k
views
how to set skb->priority of ARP packets
As the title already specifies, I'm looking for a way to set the linux skb->priority of outgoing ARP packets of a given interface on my linux machine that is used as a router.
The skb priority is ...
0
votes
1
answer
1k
views
How do I add a persistent static ARP entry to an AIX server?
How do I add a persistent static ARP entry to an AIX server?
/> uname -a
AIX CBDIS 3 5 000B8886D700
/> uname -v
5
/> uname -r
3
/>
0
votes
1
answer
1k
views
Martian source messages on most of the servers inside a network
On Ubuntu 16.04 and 18.04 servers, in the /var/log/syslog file, there are often Martian source messages like:
Aug 23 06:42:51 scilit-solr kernel: [5417098.171549] IPv4: martian source 255.255.255.255 ...
0
votes
1
answer
68
views
New computers can't connect to the network
Good Morning,
We have a business environment in which we have 3 Cisco 3850 PoE stacked and We manage our DHCP through our DC server.
Last weekend our UPS had a failure and switched off all outputs, ...
0
votes
2
answers
1k
views
Windows Loopback adapter not participating in local network
I have created a Windows loop back adapter with 'Obtain IP address Automatically' enabled.
ipconfig /all
Ethernet adapter LL Address:
Connection-specific DNS Suffix . :
Description . . . . ....
0
votes
1
answer
815
views
How does ARP resolution work on Windows
This question was originally posted on the Network Engineering SE site, but closed for being off-topic.
I've stumbled upon a peculiar behavior of Windows hosts in our network.
Our clients are mostly ...
0
votes
0
answers
97
views
Which other tools to use if PING fails
I have checked this question and I understand the use of traceroute, but I do not understand why I should use ARP if PING fails.
Details: I use Linux machine to ping the servers out of which some ...
0
votes
3
answers
483
views
ARP request for itself
I have two IPs assigned to the same interface (host A):
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether a4:bf:01:24:f8:7c brd ff:ff:ff:...
0
votes
0
answers
1k
views
Windows 10 hosts ARPing for WINS server in remote network
Our Win10 hosts are located in IP network 172.16.0.0/21.
The (remote) WINS server is located in IP network 192.168.1.0/24.
Running Wireshark on one of the hosts in 172.16.x.x I can see the entire ...
0
votes
0
answers
148
views
ARP broadcasts even when found in local cache
I have few win2012 servers that I just discovered ARP broadcasts are being generated even though the entries are found in it's local arp cache. My understanding is that if it's already on the servers ...
0
votes
1
answer
69
views
Ethernet switch forgets me too soon
My workstation is connected to one of the corporate ethernet switches. There are multiple VLANs. ipv4 broadcast and ipv6 FF02::1 only work within current VLAN.
I have enabled wake on lan and waking ...
0
votes
0
answers
660
views
arp table doesn't show entry for macvlan interface after recent ping
Using Dedicated server.
Main IP on eth0: 88.99.102.103
Default route: 88.99.102.65
Additional IP: 88.99.102.116 has MAC: 00:50:56:00:C4:6E
Creating macvlan interface:
ip link add link eth0 mac0 ...
0
votes
0
answers
380
views
windows dhcp server add static arp
in our network, Windows DHCP server 2008 broadcast Gateway's IP as router, recently some Laptop Client (most of them has personal ESET firewall installed by owners) start to get wrong arp for gateway, ...