Difference between revisions of "MAC address flooding"
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=== Allow legal traffic and discard rest. No logging === | === Allow legal traffic and discard rest. No logging === | ||
| − | If you want the port | + | If you want the port continue forwarding traffic from five MAC-addresses and discard remaining traffic and you ''don't'' want to log the attempt to use more than five MAC-addresses, use: |
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Switch(config)# interface fastethernet 0/1 - 24 | Switch(config)# interface fastethernet 0/1 - 24 | ||
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=== Allow legal traffic and discard rest. SNMP trap logging === | === Allow legal traffic and discard rest. SNMP trap logging === | ||
| − | If you want the port to | + | If you want the port continue forwarding traffic from five MAC-addresses and discard remaining traffic and you want to log the attempt to use more than five MAC-addresses. [[SNMP]] traps are sent, use: |
<pre> | <pre> | ||
Switch(config)# interface fastethernet 0/1 - 24 | Switch(config)# interface fastethernet 0/1 - 24 | ||
Revision as of 19:17, 7 May 2009
Contents
What is MAC address flooding
MAC address flooding is an attack where the attacker sends lots of frames to the switch with random source MAC addresses and flooding the MAC-address table in the switch. The CAM - Content Addressable Memory - gets full, and frames from valid hosts are flooded out of all ports.
Protecting against MAC Address flooding
Is done on a port basis.
Example
Up to five MAC address are allowed on user ports.
Port shutdown
If you want the port to go in err-disabled if more than five MAC-addresses are seen on the port
Switch(config)# interface fastethernet 0/1 - 24 Switch(config-if)switchport port-security maximum 5 Switch(config-if)switchport port-security violation shutdown
Allow legal traffic and discard rest. No logging
If you want the port continue forwarding traffic from five MAC-addresses and discard remaining traffic and you don't want to log the attempt to use more than five MAC-addresses, use:
Switch(config)# interface fastethernet 0/1 - 24 Switch(config-if)switchport port-security maximum 5 Switch(config-if)switchport port-security violation protect
Allow legal traffic and discard rest. SNMP trap logging
If you want the port continue forwarding traffic from five MAC-addresses and discard remaining traffic and you want to log the attempt to use more than five MAC-addresses. SNMP traps are sent, use:
Switch(config)# interface fastethernet 0/1 - 24 Switch(config-if)switchport port-security maximum 5 Switch(config-if)switchport port-security violation restrict
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