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3
votes
2answers
55 views

What is stopping our UDP packets (how does it know the route is down)?

We have a server (camera) sending RTSP video packets via UDP. At a customer site it travels over several hops, one of which may be an unreliable WiFi link that drops the odd packet or five. Usually ...
4
votes
2answers
137 views

Linux does not reply to ARP request messages if requested IP address is associated with another (disabled) interface

I have a PC(kernel 3.2.0-23-generic) which has 192.168.1.2/24 configured to eth0 interface and also uses 192.168.1.1 and 192.168.1.2 addresses for tun0 interface: root@T42:~# ip addr show 1: lo: ...
4
votes
1answer
38 views

Monitoring ARP Poisoning

How to monitor ARP poisoning? These few days my internal website that can be accessed locally has weird image replacing every images on the site for few seconds (it got back to normal after ...
2
votes
0answers
31 views

Publishing an ARP entry

I'm experimenting with a spoofed IP connection, as described in section 7 of this article (IP SPOOFING with BSD RAW SOCKETS INTERFACE). Indeed, when a SYN is sent with no regard for ARP, there's no ...
0
votes
2answers
43 views

Unable to connect to certain IP address, but able to connect to other IP in same subnet

I'm running a 14.04.2 LTS ubuntu box in a DMZ with IP of 10.10.30.35 and I have the following network mystery. I'm trying to connect to another unix box outside the DMZ but in our internal network at ...
0
votes
1answer
39 views

Is there a way to switch interface only by interface name?

I am currently working on how to switch network interface in Linux environment. And i am experimenting on switching network interface by switching default gateway, for example switch to wlan0 when ...
0
votes
1answer
412 views

Clear the arp cache on linux, really

Both: sudo ip -s -s neigh flush all And: sudo arp -d 192.168.0.102 Instead of clearing the arp cache they seem to just invalidate entries (they will appear as incomplete). Even after some ...
1
vote
0answers
63 views

Redirect all ARP traffic from eth0 to eth1

I would like to redirect ARP traffic, but I'm struggling with arptables and ebtables. I have 2 interfaces: eth0 10.10.10.25 eth1 10.10.10.20 Both in 10.10.10.0/24 I want to redirect the ARP ...
1
vote
0answers
30 views

Automate a gratuitous ARP every x seconds

There may be another issue here, so any other questions or comments are welcome. I have a CentOS 6.6 VM running under VirtualBox. It is connected to a GNS3 topology using a UDPTunnel. Everything ...
0
votes
1answer
32 views

When using the spoofed IP option with arping no replies are returned

Host IP: 10.0.0.21 Spoofed IP: 10.0.0.112 Live IP: 10.0.0.138 When I normally run arping like: arping -c 1 -I wlan0 10.0.0.138 I receive a reply. However when I spoof the IP using a machine on ...
0
votes
1answer
128 views

How can I block outgoing ARP traffic?

My server keeps sending ARP requests and my provider is not happy with this. To find out the reason I would like to block all outgoing arp requests (so that my provider doesn't block my server again) ...
1
vote
0answers
27 views

Wireless server only allows a single client

I have a BeagleBone Black running Debian configured as an access point using hostapd and udhcpd. A node based HTTP server accepts request on port 80. The device is not connected to any wired network. ...
3
votes
0answers
1k views

Unable to start network, <IP> is already in use for device eth0, but its not

A wierd issue after we migrated some of our servers to a new DC. We assigned new IPs to all the machines and all the servers are working fine except one. It is not picking up the new IP address and ...
1
vote
1answer
830 views

Network interface not registring ARP response

I have a server with two NIC and it's running Ubuntu Server 14.04. The first one is the interface "p3p1" and it's connected to the subnet 192.168.1.0/24 with the IP 192.168.1.100. The second one is ...
1
vote
2answers
241 views

arp (where're my network devices?)

On linux there's arp command: arp -n Address HWtype HWaddress Flags Mask Iface 192.168.1.100 ether 00:55:d1:c5:f8:1b C eth0 ...
1
vote
0answers
50 views

Is arp periodically called to check connectivity?

Do most of linux implementations periodically make arp requests to check connectivity? I am trying to migrate an ubuntu virtual machine and, after migration, it just loses network connectivity.
1
vote
0answers
35 views

Prerouting issue

I have three hosts: A, B and C. Let's say host A is continuously communicating with host C (e.g. poll - response). Now, I spoof both ARP tables of host and A and C with host B and want to block ...
3
votes
1answer
186 views

ARP request with wrong IP address

I have a strange problem with a Linux router. The setup is like this: host1 === Linux router === host2 a.b.c.d --- a.b.c.e/g.h.i.j --- g.i.h.k Every five minutes host1 tries to reach host2. ...
0
votes
2answers
2k views

How to check if ARP is enabled or not

I have enabled the arp support on my dell based server running linux on it. I wanted to check that if arptables are enabled or not. Could anyone tell me how do I check the same? Is it enough to run ...
1
vote
3answers
631 views

Different ARP results between host and virtual machine

Recently, using VMWare Player, I have configured a Linux virtual machine on a Windows host. I set the network adapter to be a bridged network with the Replicate option checked. The IP address was on ...
1
vote
0answers
731 views

OpenWrt: Find neighbors knowing their MAC address

I have an Open Mesh access point connected to the same router (an Aerohive BR100) than an Axis camera. I would like to automate the discovery of the camera's IP from inside the Open Mesh sensor, ...
3
votes
2answers
7k views

No MAC corresponding to IP in `arp` table: how to troubleshoot?

I've got a Debian 7 linux machine and a TP-link MR3020 router attached to it via ethernet cable at eth0 interface, working in WISP mode meant to make it a client rather than an access point: I also ...
11
votes
2answers
10k views

Can one ping a NIC by MAC

I have an NIC card on a Debian machine somewhere. The machine is turned off, but I need to know whether the NIC card is turned on so that I can send a wake-on-lan magic packet later (from another ...
1
vote
1answer
487 views

What does the route Dest: 123.123.123.123, GW: 0.0.0.0 mean?

I have a route table: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 123.123.123.123 0.0.0.0 255.255.255.255 UH 0 0 0 ...
0
votes
2answers
49 views

Determine users of nearby machine from CLI

Ok, so at my house I have three computers, and I frequently enjoy using ssh and scp to run commands that allow me to do wonderful things. Primarily transferring downloaded files, and running media ...
1
vote
1answer
171 views

IPs that I bound keep stop responding to ping

So Internic sent over a few cs, and it seems fine on some of them. However, on some I have to run arping -U on to get them up and they only seem to stay up for a short time. They are a /24 properly ...
1
vote
1answer
179 views

Point IP to an application instance

I was just wondering how I go about pointing a static IP address which I have purchased to an application instance on my server, using a different IP from the one I currently have pointing to my main ...
5
votes
2answers
346 views

How to prevent arp-scan from writing to syslog?

I am using arp-scan in a bash script to verify that a host is reachable. I have the script setup as a cron job that runs every minute and /var/log/syslog is filling up with the arp-scan output. I ...
3
votes
1answer
1k views

arping equivalent for IPv6

What is an equivalent for IPv6 of arping -q -c 3 -A -I [device] [ip]? I know, there is not an arp in IPv6 and Neighbor solicitation used instead, but which linux user space tool can send such ...
1
vote
1answer
418 views

How to limit all tcp traffic to the network interface the session was initiated on?

I have an embedded linux system with two network interfaces (lan0, wlan0) that are configured to the same subnet. A server on this system accepts tcp connections on both interfaces. How I can assure ...
2
votes
1answer
4k views

sysctl parameter for correct ARP response

I have a server that has some VMs, but the VMs can't communicate properly with the server because the server has several interfaces, and it responds on the wrong one. Q: We know that there is a ...
3
votes
1answer
2k views

eth0 is proxy-arping, but /proc/sys/net/ipv4/conf/eth0/proxy_arp is 0

I'm scratching my head about this question... I have a debian squeeze machine that is connected to an internal lab network. We have a lot of machines that have default proxy-arp configurations on ...