Great question, yes it will still work. RSPAN doesn't have subnet/addressing information, it only takes a copy of the traffic from the source port or vlan, sends it to the remote vlan, then the far end switch takes the traffic from the remote vlan and sends it to the destination interface (where likely your sniffer/nms would be connected.
Switches send packets as unicasts unless it needs to find out which port a MAC address (destination) is on. SPAN is used to copy frames going through an interface over to another interface where likely a packet analyzer is connected.
Hi Emmanuel, Thank you! Whether or not you need to specify the reflector port is dependent on switch hardware. For the most part, newer switches don't require specifying a reflector port.
Thanks for explaining , But how do we get to know if we need to configure a reflector port on my Switch or not ? Any hardware specification we need to check here ?
The easiest explanation I was looking for
Thanks!
Question. Would this still work if PC1 (192.168.1.1) was in a different subnet then the sniffer (Let say its in 172.31.16.1)?
Great question, yes it will still work. RSPAN doesn't have subnet/addressing information, it only takes a copy of the traffic from the source port or vlan, sends it to the remote vlan, then the far end switch takes the traffic from the remote vlan and sends it to the destination interface (where likely your sniffer/nms would be connected.
hey i have a question
if there is no vlans at all in the switch
and is on broadcast mode
why i need this span?
Switches send packets as unicasts unless it needs to find out which port a MAC address (destination) is on. SPAN is used to copy frames going through an interface over to another interface where likely a packet analyzer is connected.
Nice explanation. You made this seem real elementary. How come you didn't have to declare a "Reflector Port" though?
Hi Emmanuel,
Thank you! Whether or not you need to specify the reflector port is dependent on switch hardware. For the most part, newer switches don't require specifying a reflector port.
Thanks for explaining , But how do we get to know if we need to configure a reflector port on my Switch or not ? Any hardware specification we need to check here ?
the vlan 50 has the IP192.168.1.1 and 192.168.1.10 from the pc1 and sniffer pc respectively?
+DAvid Santana Yes, they are both in the same subnet on different switches
I had to enter command "show monitor session 1" as "show monitor" wouldn't work
Thanks for the fyi!
it's interesting you don't have to add the interfaces to the vlan50...nice tutorial thank you
Our sniffer is in VLAN 50 but not the others.
thank you so much :)
You're welcome!
Thanks.