Ask Ubuntu Stack Exchange
Ask Ubuntu Stack Exchange

Questions tagged [arp]

30 questions
6
votes
2 answers

How to protect from ARP spoofing

In my campus, some people they are using netcut in Windows and they are blocking us not to use Internet. Since I am a Ubuntu user, I can't install neither nutcut nor netcut-defender to protect and even I tried TuxCut. It's is also not working…
Suresh
  • 329
  • 1
  • 5
  • 10
4
votes
2 answers

Problems while switching IP and MAC adresses

I've got two Ubuntu-Servers, each of them with two Ethernet cards. I'm trying to switch from one to the other for high availability purposes. Unfortunately, when querying arp I always get the MAC address of the first card (eth0) and not the one of…
dan
  • 41
  • 3
3
votes
2 answers

How to format arp -a output?

I'm trying to format arp -a output to my liking. For example at the moment it outputs: MyRouter (172.16.3.x) at XX:XX:XX:XX:XX:XX [ether] on eth0 PC1 (172.16.3.x) at XX:XX:XX:XX:XX:XX [ether] on eth0 PC2 (172.16.3.x) at XX:XX:XX:XX:XX:XX [ether] on…
Reno
  • 33
  • 3
3
votes
2 answers

Get the MAC address of a connected, unlabeled, unconfigured, unconfigurable ethernet device?

Suppose you have some embedded board with ethernet plugged into the ethernet port on your laptop. You know nothing about it's network configuration (yet). You know it boots, but it is headless and only has an ethernet port. It does NOT have an ip…
Andrew Wagner
  • 416
  • 6
  • 15
2
votes
1 answer

Policy Routing - host sending ARP requests for non-local networks

I'm in need of some assistance troubleshooting a policy routing issue. I have a linux host with multiple VLANs. I'm trying to create a unique routing table for each VLAN (20 in this example) and I can ping bidirectionally between the host and the…
user2081470
  • 21
  • 4
2
votes
0 answers

static mapping between ipv6 address and MAC (equivalent to static arp in ipv4)

I want to define in static mapping between ipv6 address and MAC address.(something similar to static arp in ipv4). (i need to do this because my ubuntu machine is connected by lan to interface that don't use the kernel stack for receiving the…
Eyal leshem
  • 121
  • 4
2
votes
1 answer

Finding all used IP addresses within a LAN without assigning an IP address to your NIC?

Is there any way that you can find all the IP addresses within a LAN without assigning a IP address to you NIC? I know most of the tools like angryipscanner, arp-scan, nmap and others can mostly identify the hosts within a particular IP range and…
mario
  • 23
  • 2
1
vote
0 answers

ARP Cache Not Caching Virtual Host IP

I'm using a web application known as IOU-Web. This application is used to execute CISCO IOS software in a browser. Here is what topology looks like And here is what interfaces config snap Now the idea is that R1 should be able to access the host…
Ahmad Nadeem
  • 31
  • 1
1
vote
0 answers

No ping between two 22.04 laptops but can ping both ways from 3rd (windows) device

I have a subnet 192.168.100.x where all IPs a served DHCP over WiFi. I have XPS laptop 192.168.100.121 (Ubuntu 22.04) Inspiron laptop 192.168.100.107 (Ubuntu 22.04) Windows laptop 192.168.100.113 (Windows 10) Many other devices on the same…
Shaped Sundew
  • 11
  • 2
1
vote
0 answers

Unexpected linux neiboring subsystem behaviour when work with bridge

This is a question about linux neighboring subsystem and virtual bridge(linux is new to me,sorry for that). The test is performed on UBUNTU21(uname -a): Linux dlw 5.11.0-16-generic #17-Ubuntu SMP Wed Apr 14 20:12:43 UTC 2021 x86_64 x86_64 x86_64…
linuxer-li
  • 11
  • 1
1
vote
0 answers

Nmap keeping crashing and popping up the "System Program problem detected", should I worry?

$ sudo nmap -vv -P -T1 192.168.0.1/24 Output: >Warning: The -P option is deprecated. Please use -PE >Starting Nmap 7.80 ( https://nmap.org ) at 2021-01-01 18:29 -03 >Initiating ARP Ping Scan at 18:29 >Scanning 255 hosts [1 port/host] >nmap:…
user197536
  • 39
  • 1
  • 5
1
vote
0 answers

Ethernet stops communicating, ARP cache shows mostly incompletes

I have an Ubuntu 18.04.5 LTS, system on an AMD 64bit system with 16 GB. Recent Zoneminder install has cranked up traffic. But I did not use this system much prior to the ZM install. After a while (minutes to hours), the system stops communicating.…
avgjoetx
  • 11
  • 3
1
vote
0 answers

Issue with DHCP client/service on boot, works if run manually but with errors

I recently followed this guide to get wireless working on a fresh install of Ubuntu 19.10: https://www.linuxbabe.com/ubuntu/connect-to-wi-fi-from-terminal-on-ubuntu-18-04-19-04-with-wpa-supplicant#comment-46373 On boot the DHCP service runs and I…
BaconDuctTape
  • 113
  • 7
1
vote
1 answer

ip neigh display a mac address at a coffee store

I am working at a coffee store and tried command ip user@host:~$ ip neigh 192.168.1.1 dev wlp3s0 lladdr 5c:dd:70:96:80:52 REACHABLE I am aware that 192.168.1.1 is the router address, How about 5c:dd:70:96:80:52? is it a mac?
Alice
  • 1,640
  • 3
  • 18
  • 36
0
votes
1 answer

How to make nmap consult arp table

I want to use nmap in a subnet with the following command: nmap -T3 -F 192.168.1.0/24 My net has some interferences that make broadcast packets to be lost, so I add to my arp table the mac and ip to avoid sending arp requests, but nmap doesn't…
Check
  • 3
  • 2
1
2