Hello,

I'm running Backtrack 5 on in an VM (VMware Workstation) and I am getting troubles when I try to do a arpspoof on our LAN Network (not an other VM).
Doing this I'm getting this error:
Code:
arpspoof: couldn't arp for host 192.168.123.254
The LAN Computer's Network Address is: 192.168.123.102

Im doing to following things for ARP Spoofing:
Code:
cat /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/ip_forward
cat /proc/sys/net/ipv4/ip_forward

screen
arpspoof -t 192.168.42.254 192.168.123.102
CTRL+a S (Split)
CTRL+a TAB (Jumping to next display region)
CTRL+a C (Create the session in region)
arpspoof -t 192.168.42.102 192.168.123.254
The first one giving me an result, but the second one (arpspoof -t 192.168.123.102 192.168.42.254) gives the error I gave above.

My ifconfig looks like this:
Code:
eth1      Link encap:Ethernet  HWaddr 00:0c:29:27:8d:30  
          inet addr:192.168.42.135  Bcast:192.168.42.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe27:8d30/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1446 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2823 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:89969 (89.9 KB)  TX bytes:148952 (148.9 KB)
          Interrupt:19 Base address:0x2024
If anyone could help me, I would really apriciate that
If any more information is needed, tell me

Regards,
Melvin Koopmans