Hi,
Only just found out about The Dude so i’m a bit behind the times here!
Just installed it and found that only half the machines on my network are giving me information, including my own!
The one’s that do work, work great but the others only give me PING and NETBIOS.
I’ve tried to resolve this before asking you guys but i’m getting annoyed now as this software seems great! - here’s what i’ve tried on my own machine.
OS is WIN7 (RC1 on my own machine but having same problem on XP machines and WIN2K3)
SNMP and WMI is installed and services are running.
Firewall is turned off
AntiV is disabled
SNMP and WMI seem to work as i also use Spiceworks (where i found out about this software) which also uses the same and that works - showing me lots of info
What am i doing wrong here!
Also i have two Managed switches HP models that aren’t showing me any other info than PING - should they show me more info?
Many thanks guys…
Fire up wireshark and watch what happens to a non working one is going to be the quickest way to see…
Ok so i installed WireShark and here’s what i’ve found - My machine receives TCP and SNMP packets no problems, however from my machine back to the The Dude server i’m seeing TCP errors with [TCP CHECKSUM INCORRECT] after it.
when you look at more details it shows what it thinks is the checksum and what it should be and then the text (maybe caused by “TCP checksum offload”?)
Any thoughts on what this might be and how to go about rectifying it?
If TCP checksum offload is enabled on the sniffing machines NIC you’ll get this in Wireshark. It is usually not an error, but a feature. The NIC is calculating the checksum of the packets instead of the CPU. This makes Wireshark think that the checksum is off because it intercepts the packets with the wrong checksum. You can disable the TCPCO in the NIC driver settings.
Read about it here:
h**p://wiki.wireshark.org/TCP_checksum_offload
Yeah I should have warned you about checksum errors, I disable that feature. You just need to compare capture capture results with a working system. Are all the machines snmp v2 capable? Most likely they are… Are you using v1 or v2?