IP stops broadcasting when sshed to.

Bug #1711460 reported by Scott Cohen
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Ubuntu MATE
Invalid
Undecided
Unassigned
arp-scan (Ubuntu)
New
Undecided
Unassigned

Bug Description

When I do a scan of my local network via the command arp-scan --localnet, I find that the IP of the machine which has Ubuntu-MATE on it shows up in the list of IPs brought back by arp-scan. But when I ssh to that machine and then issue the command arp-scan --localnet from the machine that I had sshed from, I find that the IP address of the computer with Ubuntu-MATE on it is absent from the list. I'm not sure what information I can give other than my list of installed packages and that I'm running Ubuntu-MATE 17.10 getting updates from the developer repository.

I posted a bug report here: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1711465
This has more thorough data if applicable.

Revision history for this message
Scott Cohen (yetoo) wrote :
Scott Cohen (yetoo)
description: updated
Scott Cohen (yetoo)
description: updated
Revision history for this message
nadrimajstor (ipejic) wrote :

AFAIK, As arp-scan will show data for packets that went trough the interface, you won't see ARP request/reply to itself (as those will not "reach the wire"). Hence, the "missing" local IP/MAC pair.
IINM, You can observe same behavior on any other linux system and with other tools (netdiscover, tcpdump).
(I agree that this behavior does make additional cognitive load - It will easily show duplicate IP address for other hosts but for your own host you have to keep in mind that your IP/MAC is missing from the report)

Revision history for this message
Scott Cohen (yetoo) wrote :

So, if I understand correctly, this an issue with the arp-scan package?

Revision history for this message
nadrimajstor (ipejic) wrote :

I believe so.
If my understanding on how tools that relay on libpcap works (arp-scan, netdiscover, ...) this could be a feature request for them.
For example, netdiscover beside active mode (that arp-scan also use) it have an additional passive mode, where it does not send ARP requests just listen for other's and it also omits local IP/MAC from report.

Changed in ubuntu-mate:
status: New → Invalid
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