2
votes
2answers
321 views

ARP responds with single MAC address on Linux server with multiple interfaces on the same network

Linux server has 2 active network interfaces: IF:eth1 IP:192.168.1.1/24 MAC:11:11:11:11:11:11 (1GbE) IF:eth2 IP:192.168.1.2/24 MAC:22:22:22:22:22:22 (10GbE) The idea is that the ...
2
votes
1answer
160 views

nmap and arp-scan inconsistent IP-MAC results

I seem to get variable and inconsistent results for the IP/MAC addresses from a particular machine, using nmap or arp-scan. The machine has 3 interfaces, and this is what it shows: $ uname -a Linux ...
0
votes
2answers
766 views

Multiple NICs with IPs from same network at Linux host respond to a single MAC

CentOS host is armed with multiple NICs. All NICs are bound to the same subnetwork (let it be 10.0.0.0/24). Their IP configuration is provided with DHCP server (as reservations). While trying to get ...
0
votes
3answers
545 views

Linux: find MAC Address for unconfigured card

I have a linux system for which I want to create my own udev rules for the nic. Currently there are no rules, so no ethX is configured. I can't do ifconfig (it is not showing any interfaces besides ...
2
votes
4answers
341 views

Newbie questions on MAC and high availability failovers

I am reading about High Availability and I can not understand the following I read: On failover the primary IP migrates to the backup server BUT so must the MAC address. Specifically I read that ...
1
vote
3answers
453 views

Get the MAC addresses of all the machines connected to a LAN when NO machines have got an IP address yet

Here is the real scenario. I have say 4 machines not having any IP address yet connected to a switch. In one of the machines (OS=CentOS), I would install a DHCP server and would provide the other ...
0
votes
2answers
752 views

Tie SSH key with MAC address

I have a ubuntu server which I scp files to often. It is setup for password-less authentication using a key I have on the server. Is it possible to tie a mac address to the key so that only my client ...
6
votes
1answer
2k views

Is bonding mode=5 a solution against MAC flapping?

There is two are interconnected Cisco WS-2950T. By the one GBIC port on first switch connected a first NIC of bonding interface, and by the one GBIC port on second switch connected a second NIC of ...
3
votes
1answer
2k views

Ubuntu Linux - two interfaces, same subnet, different vlan - MAC/ARP issues

I'm attempting to setup a server that needs to have interfaces on the same IP subnet, but different VLANs: eth1.102 Link encap:Ethernet HWaddr 00:50:56:b1:00:0f inet addr:10.1.1.6 ...
2
votes
3answers
530 views

On CentOS 4.5, How to Masquerade a connection using MAC address?

Currently we give Internet access using ip address in our firewall script as follows iptables -t nat -A POSTROUNTING -s 192.168.1.40 -j MASQUERADE But we have noticed that some guys steal these ...
-1
votes
2answers
876 views

Get client's MAC address when connecting with SSH

I want to get the MAC address of every machine that connects via SSH to my server. Is this possible? If yes, can you provide me some references? Thank you in advance!
0
votes
2answers
215 views

About the MAC table on switches?

I'm learning the network basics at my university this semester. I had a question on the mid-term exam and unfortunately ,I answered it wrong. I have a final exam about an hour from now, and I still ...
1
vote
2answers
530 views

Counting traffic to destination MAC address using ebtables/iptables

I would like to be able to count the number of bytes going to a given MAC address using iptables or ebtables or some other linux utility. I have tried looking at the byte counts in ebtables but they ...
5
votes
2answers
1k views

Can I get the original MAC address after it has been changed?

I am using some linux machines that have had their MAC address changed. I would like to be able to read it back with a shell script. Is the original MAC address stored anywhere except the sticker on ...
1
vote
4answers
142 views

Linux - Is there a way to determine what mac addresses an interface has seen traffic from?

Yes, I know about ARP but that relies somewhat on IP layer connectivity in that the remote system must be configured with an IP on a recognized subnet. Is there any way to just dump off what mac ...
7
votes
4answers
4k views

how to generate a random MAC address from the Linux command line

How do I generate a random MAC address from the Linux command line? I search for a solution that only requires standard tools commonly found on the Linux command line. The MAC address will be used ...
1
vote
4answers
430 views

Is there a tool like 'route' in Linux to configure the forwarding entry (dst mac address --> interface)

I have a problem in configuring the forwarding table in Linux. We call IP tables for routing table in layer 3, MAC tables for forwarding table in layer 2. Now I want to add an entry in forwarding ...
4
votes
5answers
1k views

DHCPDISCOVER requests from an off-by-one MAC address

In a Linux DHCP server I'm getting a bunch of these log lines: dhcpd: DHCPDISCOVER from 00:30:48:fe:5c:9c via eth1: network 192.168.2.0/24: no free leases I don't have any machines with ...
0
votes
4answers
885 views

MAC address filtering in Linux

I'm a new system administrator of an existing Linux network. Apparently there is MAC address filtering there. How could I allow a specific MAC to connect to the network? The INPUT, FORWARD and OUTPUT ...
1
vote
1answer
253 views

How to prevent response to who-has requests on virtual eth interface?

we use small embedded X86 linux servers equipped with a single physical ethernet port as a gateway for an IP video surveillance application. Each downstream IP cam is mapped to a separate virtual IP ...
0
votes
4answers
2k views

Is there a way to determine if a certain MAC address is on the local network from a Synology Cubestation, which doesn't have arp?

I have a bit of a strange problem, I am trying to determine if a certain MAC address (my xbox 360) is on the network (i.e. on) The problem is i'm doing it from my Synology Cubestation, which is a ...
4
votes
6answers
2k views

MAC Address Spoofing/Changing Software

What is the best MAC address changing/spoofing/editing program available for windows, mac and linux?