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--- cisco:switch [2009/03/11 18:12]
a
+++ cisco:switch [2011/11/24 13:34] (current)
greebo
@@ Line 8: / Line 8: @@
   * **traffic with dest. mac addresses unknown to the switch, which is flooded to all ports but the one where the packets entered.** \\
-When one uses "''**switchport block unicast**''", the third type on the list, the so called "''unknown unicast''" traffic is noe forwarded to the specific port, so the only traffic exiting the port will be the broadcast (ff...) or the packets that have as destination mac, one of the mac-addresses learned on the port. \\
+When one uses "''**switchport block unicast**''", the third type on the list, the so called "''unknown unicast''" traffic is not forwarded to the specific port, so the only traffic exiting the port will be the broadcast (ff...) or the packets that have as destination mac, one of the mac-addresses learned on the port. \\
 \\
 A problem arises when a host connected somehow to that port does not send any traffic for more than ''$mac_address_aging_time'' (usually 5 min): the mac will be erased from the mac address table, and the traffic will
@@ Line 20: / Line 20: @@
 for each interface
+===== Make Catalyst switch silent (The Invisible Catalyst Switch) =====
+<note tip>
+If you've ever looked at a packet capture from a Cisco Catalyst switch with a default configuration, you know they produce a good amount of ambient noise out of the box. CDP, STP, DTP, keepalives - these are all turned on by default and, combined, generate a significant amount of traffic. \\
+**Original notes: http://packetlife.net/blog/2010/apr/15/invisible-catalyst-switch/ (10x Jeremy Stretch)**
+</note>
+**Turning off CDP**
+   S1(config)# no cdp run
+**Turning off DTP**
+   S1(config)# interface range f0/1 -24
+   S1(config-if-range)# switchport mode access
+   S1(config-if-range)# switchport nonegotiate
+**Turning off STP**
+   S1(config)# no spanning-tree vlan 1
+**Turning off Ethernet Keepalives**
+   S1(config)# interface range f0/1 -24
+   S1(config-if-range)# no keepalive
 ===== Security on L2 based equipment =====