06-04-2014 12:42 PM
Hello,
I wanted to ask some advice on a concept that has bothered me for a while.
I have been deploying cisco SG300 series switches in our network infrastructures that we build out for a while now, but i would like to make some adjustments in regards to security. Here is the general idea of our existing network layouts:
Core switch:
Management VLAN: 1
1 trunk port going to our router
-native VLAN 1
-tagged vlans 999-1500
trunk ports going to other switches in the network
-native VLAN 1
-tagged vlans 999-1500
Edge switches:
Management VLAN 1
1 trunk port going back to core switch
-native VLAN 1
-tagged vlans 999-1500
Remainder of ports are trunk ports which connect wireless access points
-native VLAN 1
-tagged vlans 999-1500
-wireless users may be on any VLAN between 999-1500 (assigned dynamically by radius server)
My goal is to tighten up security in order to prevent VLAN hopping.
I am thinking of the following changes specifically:
-change switch management VLAN to 99
-change access point ports to have native VLAN of 99
-change interswitch uplink ports native VLAN to something else (10)
My questions are:
Should I change the switch management VLAN to 10 instead? or 99?
Will this prevent VLAN hopping as intended?
Should i configuring the ports to send default-vlan traffic as tagged instead of untagged (switchport default-vlan tagged)?
Am I misunderstanding something?
thanks in advance for any help/suggestions!
06-04-2014 02:34 PM
Could someone let me know if the following configurations adhere to the best practices and prevent vlan hopping attacks, or if I'm missing something crucial?
CORE SWITCH
vlan database
vlan 99,999-1500
exit
!
interface vlan 99
ip address 192.168.5.6 255.255.255.0
no ip address dhcp
!
interface gigabitethernet27
description "uplink to edge switch"
switchport trunk allowed vlan add 99,999-1500
switchport trunk default-vlan tagged
!
interface gigabitethernet28
description "uplink to router"
switchport trunk allowed vlan add 99,999-1500
switchport trunk default-vlan tagged
!
EDGE SWITCH
vlan database
vlan 99,999-1500
exit
!
interface vlan 99
ip address 192.168.5.7 255.255.255.0
no ip address dhcp
!
interface gigabitethernet1
description "AP port"
switchport trunk allowed vlan add 999-1500
switchport trunk native vlan 99
switchport trunk default-vlan tagged
!
interface gigabitethernet10
description "uplink to core switch"
switchport trunk allowed vlan add 99,999-1500
switchport trunk default-vlan tagged
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide