How to set port mirroring?

[jilingshu]

hi all,
I wanna set a port mirroring to monitor all traffic in LAN interface. I have searched this forum and found someone said I can use "dup-to" to do this(http://forum.pfsense.org/index.php?action=printpage;topic=14334.0). But he said no details. So could u tell me some more information on this? thx!

[0tt0]

@jilingshu:

hi all,
I wanna set a port mirroring to monitor all traffic in LAN interface. I have searched this forum and found someone said I can use "dup-to" to do this(http://forum.pfsense.org/index.php?action=printpage;topic=14334.0). But he said no details. So could u tell me some more information on this? thx!

Kinda interesting, but I wouldn't burden the firewall with that, have the switch do the work if possible.

http://en.wikipedia.org/wiki/Port_mirroring

[Cry Havok]

Or install a network tap - you can even find information on building them.

[MarcoP]

Nice article, indeed.

Where I live, building the tap will cost around $80, $100;
a ProCurve 8 ports managed switch with port mirroring will only cost $110, $140 ;)

[jilingshu]

@0tt0:

@jilingshu:

hi all,
I wanna set a port mirroring to monitor all traffic in LAN interface. I have searched this forum and found someone said I can use "dup-to" to do this(http://forum.pfsense.org/index.php?action=printpage;topic=14334.0). But he said no details. So could u tell me some more information on this? thx!

Kinda interesting, but I wouldn't burden the firewall with that, have the switch do the work if possible.

http://en.wikipedia.org/wiki/Port_mirroring

hi,
The problem is that I have no switch with port mirroring function… My switch is so cheap(50RMB, about $7) to have any functions except connecting all computers together...

I only need to sniff traffic between LAN and WAN so I think make a port mirroring my firewall is suitable. ;)