chapter 6 - leaman
TRANSCRIPT
CCNA Security
1© 2009 Cisco Learning Institute.
Chapter Six
Securing the Local Area Network
Major Concepts
• Describe endpoint vulnerabilities and protection methods
• Describe basic Catalyst switch vulnerabilities
• Configure and verify switch security features,
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• Configure and verify switch security features, including port security and storm control
• Describe the fundamental security considerations of Wireless, VoIP, and SANs
Lesson Objectives
Upon completion of this lesson, the successful participant will be able to:
1. Describe endpoint security and the enabling technologies
2. Describe how Cisco IronPort is used to ensure endpoint security
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3. Describe how Cisco NAC products are used to ensure endpoint security
4. Describe how the Cisco Security Agent is used to ensure endpoint security
5. Describe the primary considerations for securing the Layer 2 infrastructure
6. Describe MAC address spoofing attacks and MAC address spoofing attack mitigation
Lesson Objectives
7. Describe MAC Address table overflow attacks and MAC Address table overflow attack mitigation
8. Describe STP manipulation attacks and STP manipulation attack mitigation
9. Describe LAN Storm attacks and LAN Storm attack mitigation
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10. Describe VLAN attacks and VLAN attack mitigation
11. Describe how to configure port security
12. Describe how to verify port security
13. Describe how to configure and verify BPDU Guard and Root Guard
14. Describe how to configure and verify storm control
15. Describe and configure Cisco SPAN
16. Describe and configure Cisco RSPAN
Lesson Objectives
17. Describe the best practices for Layer 2 security
18. Describe the fundamental aspects of enterprise security for advanced technologies
19. Describe the fundamental aspects of wireless security and the enabling technologies
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20. Describe wireless security solutions
21. Describe the fundamental aspects of VoIP security and the enabling technologies Reference: CIAG course on VoIP security.
22. Describe VoIP security solutions
23. Describe the fundamental aspects of SAN security and the enabling technologies
24. Describe SAN security solutions
Securing the LAN
MARS
VPN
ACS
Firewall
Perimeter
Internet
Areas of concentration:• Securing endpoints• Securing network
infrastructure
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IPSVPN
Iron Port
Web Server
Email Server DNS
LAN
Hosts
infrastructure
Policy Compliance
Infection Containment
Secure
Addressing Endpoint Security
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Threat Protection
SecureHost
Based on three elements:• Cisco Network Admission Control (NAC)• Endpoint protection• Network infection containment
Operating Systems Basic Security Services
• Trusted code and trusted path – ensures that the integrity of the operating system is not violated
• Privileged context of execution – provides identity authentication and certain privileges based on the identity
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• Process memory protection and isolation – provides separation from other users and their data
• Access control to resources – ensures confidentiality and integrity of data
Types of Application Attacks
I have gained direct access to this
application’s privileges
I have gained access to
Direct
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I have gained access to this system which is trusted by the other
system, allowing me to access it. Indirect
Cisco Systems Endpoint Security Solutions
IronPortCisco Security Agent
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Cisco NAC
Cisco IronPort Products
IronPort products include:• E-mail security appliances for virus
and spam control• Web security appliance for spyware
filtering, URL filtering, and anti-malware• Security management appliance
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IronPort C-Series
InternetInternet
Before IronPort
Firewall
After IronPort
Firewall
Encryption Platform
MTADLP Scanner
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Antispam
Antivirus
Policy Enforcement
Mail Routing
IronPort E-mail Security Appliance
Groupware
UsersUsers
Groupware
DLP Policy Manager
IronPort S-Series
Web Proxy
Firewall Firewall
Before IronPort After IronPort
InternetInternet
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Antispyware
Antivirus
Antiphishing
URL Filtering
Policy Management
UsersUsers
IronPort S-Series
Cisco NAC
NAC Framework
The purpose of NAC:
� Allow only authorized and compliant systems to access the network
� To enforce network security policy
Cisco NAC Appliance
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NAC Framework
• Software module embedded within NAC-enabled products
• Integrated framework leveraging multiple Cisco and NAC-aware vendor products
• In-band Cisco NAC Appliance solution can be used on any switch or router platform
• Self-contained, turnkey solution
Cisco NAC Appliance
The NAC Framework
AAA ServerCredentials Credentials
Vendor Servers
Hosts Attempting Network Access
Network Access Devices Policy Server
Decision Points and Remediation
Enforcement
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Credentials
Credentials
EAP/UDP,
EAP/802.1x
RADIUS
Credentials
HTTPS
Access Rights
Notification
Cisco Trust Agent
Comply?
NAC Components
• Cisco NAS
Serves as an in-band or out-of-band device for network access control
• Cisco NAM
• Cisco NAA
Optional lightweight client for device-based registry scans in unmanaged environments
• Rule-set updates
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• Cisco NAM
Centralizes management for administrators, support personnel, and operators
• Rule-set updates
Scheduled automatic updates for antivirus, critical hotfixes, and other applications
MGR
Cisco NAC Appliance Process
THE GOAL
Cisco NAM
1. Host attempts to access a web page or uses an optional client.
Network access is blocked until wired or wireless host provides login information. Authentication
Server
MGR
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Intranet/Network
2. Host is redirected to a login page.
Cisco NAC Appliance validates username and password, also performs device and network scans to assess vulnerabilities on device.
Device is noncompliant or login is incorrect.
Host is denied access and assigned to a quarantine role with access to online remediation resources.
3a.3b. Device is “clean”.
Machine gets on “certified devices list” and is granted access to network.
Cisco NAS
QuarantineRole
3. The host is authenticated and optionallyscanned for posture compliance
Access Windows
LoginScreen
Scan is performed(types of checks depend on user role)
Scan fails
Remediate
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4.
CSA Architecture
Server Protected by Cisco Security Agent
Administration Workstation
EventsAlerts
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Management Center for Cisco Security Agent
with Internal or External Database
SecurityPolicy
SSL
CSA Overview
File System
Interceptor
Network
Interceptor
Configuration
Interceptor
Execution
Space
Interceptor
Application
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State Rules and Policies
RulesEngine
CorrelationEngine
Allowed Request
Blocked Request
CSA Functionality
Security ApplicationNetwork
Interceptor
File System
Interceptor
Configuration
Interceptor
Execution
Space
Interceptor
Distributed Firewall X ― ― ―
Host Intrusion X ― ― X
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Host Intrusion
PreventionX ― ― X
Application
Sandbox― X X X
Network Worm
PreventionX ― ― X
File Integrity Monitor ― X X ―
Attack Phases
Server Protected by
Cisco SecurityAgent
– Probe phase
• Ping scans
• Port scans
– Penetrate phase
• Transfer exploit code to target
– Persist phase
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– File system interceptor– Network interceptor– Configuration interceptor– Execution space
interceptor
Agent• Install new code
• Modify configuration
– Propagate phase
• Attack other targets
– Paralyze phase
• Erase files
• Crash system
• Steal data
CSA Log Messages
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MARS
ACS
Firewall
Perimeter
Internet
Layer 2 Security
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IPSVPN
Iron Port
Web Server
Email Server DNS
Hosts
Internet
OSI Model
When it comes to networking, Layer 2 is often a very weak link.
Application StreamApplication
Presentation
Co
mp
rom
ise
d
Application
Presentation
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MAC Addresses
Physical Links
IP Addresses
Protocols and Ports
Session
Transport
Network
Data Link
Physical
Co
mp
rom
ise
dSession
Transport
Network
Data Link
Physical
Initial Compromise
MAC Address Spoofing Attack
MAC Address: AABBcc
AABBcc 12AbDdSwitch Port
1 2The switch keeps track of theendpoints by maintaining aMAC address table. In MAC spoofing, the attacker posesas another host—in this case,AABBcc
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AABBcc
MAC Address: AABBcc
Attacker
Port 1
Port 2
MAC Address: 12AbDd
I have associated Ports 1 and 2 with the MAC addresses of the devices attached. Traffic destined for each device will be forwarded directly.
MAC Address Spoofing Attack
AABBcc
Switch Port
1 2
Attacker
AABBcc
1 2I have changed the MACaddress on my computer to match the server.
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MAC Address: AABBcc
MAC Address: AABBcc
Port 1 Port 2
The device with MAC address AABBcc has changed locations to Port2. I must adjust my MAC address table accordingly.
MAC Address Table Overflow Attack
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The switch can forward frames between PC1 and PC2 without flooding because the MAC address table contains port-to-MAC-address mappings in the MAC address table for these PCs.
MAC Address Table Overflow Attack
Intruder runs macofto begin sending unknown bogus MAC addresses.
3/25 MAC X 3/25 MAC Y 3/25 MAC Z
XYZ
MAC Port
X 3/25
Y 3/25
C 3/25
Bogus addresses are added to the CAM table. CAM table is full.
12
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A B
C D
VLAN 10 VLAN 10
3/25XYZ
flood
Host C
The switch floods the frames.
Attacker sees traffic to servers B and D.
VLAN 10
3
4
STP Manipulation Attack
• Spanning tree protocol operates by electing a root bridge
• STP builds a tree topologyF F
Root BridgePriority = 8192MAC Address=
0000.00C0.1234
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• STP manipulation changes the topology of a network—the attacking host appears to be the root bridge
F F
F B
STP Manipulation Attack
Root BridgePriority = 8192
F F
F F
F B
FF
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Root Bridge
F B F F
Attacker The attacking host broadcasts out STPconfiguration and topology change BPDUs.This is an attempt to force spanning treerecalculations.
LAN Storm Attack
Broadcast
Broadcast
Broadcast
Broadcast
Broadcast
Broadcast
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• Broadcast, multicast, or unicast packets are flooded on all ports in the same VLAN.
• These storms can increase the CPU utilization on a switch to 100%, reducing the performance of the network.
Storm Control
Total number of
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number ofbroadcastpacketsor bytes
VLAN Attacks
� Segmentation
� Flexibility
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VLAN = Broadcast Domain = Logical Network (Subnet)
� Security
VLAN Attacks
802.1Q
Server
Trunk
VLAN 20
VLAN 10
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ServerAttacker sees traffic destined for servers
A VLAN hopping attack can be launched in two ways:• Spoofing DTP Messages from the attacking host to
cause the switch to enter trunking mode• Introducing a rogue switch and turning trunking on
The second switch receives the packet, on the native VLAN
Double-Tagging VLAN Attack
Attacker onVLAN 10, but puts a 20 tag in the packet
The first switch strips off the first tag and does not retag it (native traffic is not retagged). It then forwards the packet to switch 2.
20802.1Q, Frame
1
2
3
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the native VLAN
Victim(VLAN 20)Note: This attack works only if the
trunk has the same native VLAN as the attacker.
20
Trunk(Native VLAN = 10)
802.1Q, Frame3
4
The second switch examines the packet, sees the VLAN 20 tag and forwards it accordingly.
Port Security Overview
MAC A
MAC A
Port 0/1 allows MAC APort 0/2 allows MAC BPort 0/3 allows MAC C
0/1
0/2
0/3
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MAC A
Attacker 1
Attacker 2
MAC F
Allows an administrator to statically specify MAC Addresses for a port or to permit the switch to dynamically learn a limited number of MACaddresses
CLI Commands
switchport mode access
Switch(config-if)#
• Sets the interface mode as access
switchport port-security
Switch(config-if)#
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switchport port-security
• Enables port security on the interface
switchport port-security maximum value
Switch(config-if)#
• Sets the maximum number of secure MAC addresses for the interface (optional)
Switchport Port-Security Parameters
Parameter Description
mac-address mac-address (Optional) Specify a secure MAC address for the port by entering a 48-bit MAC aaddress. You can add additional
secure MAC addresses up to the maximum value configured.
vlan vlan-id (Optional) On a trunk port only, specify the VLAN ID and the MAC address. If no VLAN ID is specified, the native
VLAN is used.
vlan access (Optional) On an access port only, specify the VLAN as an access VLAN.
vlan voice (Optional) On an access port only, specify the VLAN as a voice VLAN
mac-address sticky (Optional) Enable the interface for sticky learning by entering only the mac-address sticky keywords. When sticky
learning is enabled, the interface adds all secure MAC addresses that are dynamically learned to the running
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[mac-address] learning is enabled, the interface adds all secure MAC addresses that are dynamically learned to the running
configuration and converts these addresses to sticky secure MAC addresses.
Specify a sticky secure MAC address by entering the mac-address sticky mac-address keywords..
maximum value (Optional) Set the maximum number of secure MAC addresses for the interface. The maximum number of secure
MAC addresses that you can configure on a switch is set by the maximum number of available MAC
addresses allowed in the system. The active Switch Database Management (SDM) template determines this
number. This number represents the total of available MAC addresses, including those used for other Layer 2
functions and any other secure MAC addresses configured on interfaces.
The default setting is 1.
vlan [vlan-list] (Optional) For trunk ports, you can set the maximum number of secure MAC addresses on a VLAN. If the vlan
keyword is not entered, the default value is used.
n vlan: set a per-VLAN maximum value.
n vlan vlan-list: set a per-VLAN maximum value on a range of VLANs separated by a hyphen or a series of
VLANs separated by commas. For nonspecified VLANs, the per-VLAN maximum value is used.
Port Security Violation Configuration
switchport port-security violation {protect | restrict | shutdown}
Switch(config-if)#
• Sets the violation mode (optional)
switchport port-security mac-address
Switch(config-if)#
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switchport port-security mac-address sticky
Switch(config-if)#
• Enables sticky learning on the interface (optional)
switchport port-security mac-address mac-address
• Enters a static secure MAC address for the interface (optional)
Switchport Port-Security ViolationParameters
Parameter Description
protect (Optional) Set the security violation protect mode. When the number of secure MAC addresses reaches the limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses or increase the number of maximum allowable addresses. You are not notified that a security violation has occurred.
restrict (Optional) Set the security violation restrict mode. When the number of secure MAC addresses reaches the limit allowed on the port, packets with unknown source addresses are dropped until you remove a sufficient number of secure MAC addresses
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addresses are dropped until you remove a sufficient number of secure MAC addresses or increase the number of maximum allowable addresses. In this mode, you are notified that a security violation has occurred.
shutdown (Optional) Set the security violation shutdown mode. In this mode, a port security violation causes the interface to immediately become error-disabled and turns off the port LED. It also sends an SNMP trap, logs a syslog message, and increments the violation counter. When a secure port is in the error-disabled state, you can bring it out of this state by entering the errdisable recovery cause psecure-violation global configuration command, or you can manually re-enable it by entering the shutdown and no shut down interface configuration commands.
shutdown
vlan
Set the security violation mode to per-VLAN shutdown. In this mode, only the VLAN on which the violation occurred is error-disabled.
Port Security Aging Configuration
switchport port-security aging {static | time time | type {absolute | inactivity}}
Switch(config-if)#
• Enables or disables static aging for the secure port or sets the aging time or type
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sets the aging time or type
• The aging command allows MAC-Addresses on the Secure switchport to be deleted after the set aging time
• This helps to avoid a situation where obsolete MAC-Address occupy the table and saturates causing a violation (when the max number exceeds)
Switchport Port-Security Aging Parameters
Parameter Description
static Enable aging for statically configured secure
addresses on this port.
time time Specify the aging time for this port. The range is 0 to
1440 minutes. If the time is 0, aging is disabled for
this port.
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type absolute Set absolute aging type. All the secure addresses
on this port age out exactly after the time (minutes)
specified and are removed from the secure address
list.
type inactivity Set the inactivity aging type. The secure addresses
on this port age out only if there is no data traffic
from the secure source address for the specified
time period.
Typical Configuration
S2
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switchport mode access switchport port-security switchport port-security maximum 2switchport port-security violation shutdownswitchport port-security mac-address sticky switchport port-security aging time 120
Switch(config-if)#PC B
CLI Commands
sw-class# show port-security
Secure Port MaxSecureAddr CurrentAddr SecurityViolation Security Action
(Count) (Count) (Count)
---------------------------------------------------------------------------
Fa0/12 2 0 0 Shutdown
---------------------------------------------------------------------------
Total Addresses in System (excluding one mac per port) : 0
Max Addresses limit in System (excluding one mac per port) : 1024
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sw-class# show port-security interface f0/12
Port Security : Enabled
Port status : Secure-down
Violation mode : Shutdown
Maximum MAC Addresses : 2
Total MAC Addresses : 1
Configured MAC Addresses : 0
Aging time : 120 mins
Aging type : Absolute
SecureStatic address aging : Disabled
Security Violation Count : 0
View Secure MAC Addresses
sw-class# show port-security address
Secure Mac Address Table
-------------------------------------------------------------------
Vlan Mac Address Type Ports Remaining Age
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Vlan Mac Address Type Ports Remaining Age
(mins)
---- ----------- ---- ----- -------------
1 0000.ffff.aaaa SecureConfigured Fa0/12 -
-------------------------------------------------------------------
Total Addresses in System (excluding one mac per port) : 0
Max Addresses limit in System (excluding one mac per port) : 1024
MAC Address Notification
NMS
MAC A
MAC B
F1/1 = MAC A
Switch CAM Table
SNMP traps sent to NMS when new MAC addresses appear or
when old ones time out.F1/2
F1/1
F2/1
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MAC address notification allows monitoring of the MAC addresses, at the module and port level, added by the switch or removed from the CAM table for secure ports.
MAC A F1/1 = MAC AF1/2 = MAC B
F2/1 = MAC D(address ages out)
MAC D is awayfrom the network.
Configure Portfast
Server Workstation
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Command Description
Switch(config-if)# spanning-
tree portfast
Enables PortFast on a Layer 2 access port and forces it to enter the forwarding stateimmediately.
Switch(config-if)# no
spanning-tree portfast
Disables PortFast on a Layer 2 access port. PortFast is disabled by default.
Switch(config)# spanning-tree
portfast default
Globally enables the PortFast feature on all nontrunking ports.
Switch# show running-config
interface type slot/port
Indicates whether PortFast has been configured on a port.
BPDU Guard
F F
FF
F B
Root Bridge
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Switch(config)#
spanning-tree portfast bpduguard default
• Globally enables BPDU guard on all ports with PortFast enabled
F B
BPDU Guard
Enabled
AttackerSTP
BPDU
Display the State of Spanning Tree
Switch# show spanning-tree summary totalsRoot bridge for: none.
PortFast BPDU Guard is enabled
UplinkFast is disabled
BackboneFast is disabled
Spanning tree default pathcost method used is short
Name Blocking Listening Learning Forwarding STP Active
-------------------- -------- --------- -------- ---------- ----------
1 VLAN 0 0 0 1 1
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1 VLAN 0 0 0 1 1
<output omitted>
Root Guard
Root BridgePriority = 0
MAC Address = 0000.0c45.1a5d
F F
F F
F BF
Root Guard
Enabled
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Switch(config-if)#
spanning-tree guard root
• Enables root guard on a per-interface basis
F
STP BPDUPriority = 0
MAC Address = 0000.0c45.1234Attacker
Verify Root Guard
Switch# show spanning-tree inconsistentportsName Interface Inconsistency
-------------------- ---------------------- ------------------
VLAN0001 FastEthernet3/1 Port Type Inconsistent
VLAN0001 FastEthernet3/2 Port Type Inconsistent
VLAN1002 FastEthernet3/1 Port Type Inconsistent
VLAN1002 FastEthernet3/2 Port Type Inconsistent
VLAN1003 FastEthernet3/1 Port Type Inconsistent
VLAN1003 FastEthernet3/2 Port Type Inconsistent
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VLAN1003 FastEthernet3/2 Port Type Inconsistent
VLAN1004 FastEthernet3/1 Port Type Inconsistent
VLAN1004 FastEthernet3/2 Port Type Inconsistent
VLAN1005 FastEthernet3/1 Port Type Inconsistent
VLAN1005 FastEthernet3/2 Port Type Inconsistent
Number of inconsistent ports (segments) in the system :10
Storm Control Methods
• Bandwidth as a percentage of the total available bandwidth of the port that can be used by the broadcast, multicast, or unicast traffic
• Traffic rate in packets per second at which broadcast, multicast, or unicast packets are received
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multicast, or unicast packets are received
• Traffic rate in bits per second at which broadcast, multicast, or unicast packets are received
• Traffic rate in packets per second and for small frames. This feature is enabled globally. The threshold for small frames is configured for each interface.
Storm Control Configuration
• Enables storm control
Switch(config-if)# storm-control broadcast level 75.5Switch(config-if)# storm-control multicast level pps2k 1k
Switch(config-if)# storm-control action shutdown
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• Enables storm control
• Specifies the level at which it is enabled
• Specifies the action that should take place when the threshold (level) is reached, in addition to filtering traffic
Storm Control Parameters
Parameter Description
broadcast This parameter enables broadcast storm control on the interface.
multicast This parameter enables multicast storm control on the interface.
unicast This parameter enables unicast storm control on the interface.
level level [level-low] Rising and falling suppression levels as a percentage of total bandwidth of the port.• level: Rising suppression level. The range is 0.00 to 100.00. Block the flooding of
storm packets when the value specified for level is reached.• level-low: (Optional) Falling suppression level, up to two decimal places. This
value must be less than or equal to the rising suppression value.
level bps bps [bps-low] Specify the rising and falling suppression levels as a rate in bits per second at which
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level bps bps [bps-low] Specify the rising and falling suppression levels as a rate in bits per second at which traffic is received on the port.
• bps: Rising suppression level. The range is 0.0 to 10000000000.0. Block the flooding of storm packets when the value specified for bps is reached.
• bps-low: (Optional) Falling suppression level, up to one decimal place. This value must be equal to or less than the rising suppression value.
level pps pps [pps-low] Specify the rising and falling suppression levels as a rate in packets per second at which traffic is received on the port.
• pps: Rising suppression level. The range is 0.0 to 10000000000.0. Block the flooding of storm packets when the value specified for pps is reached.
• pps-low: (Optional) Falling suppression level, up to one decimal place. This value must be equal to or less than the rising suppression value.
action {shutdown|trap} The action taken when a storm occurs on a port. The default action is to filter traffic and to not send an SNMP trap.
The keywords have these meanings:• shutdown: Disables the port during a storm• trap: Sends an SNMP trap when a storm occurs
Verify Storm Control Settings
Switch# show storm-control
Interface Filter State Upper Lower Current
--------- ------------- ---------- --------- --------
-Gi0/1 Forwarding 20 pps 10 pps 5 pps
Gi0/2 Forwarding 50.00% 40.00% 0.00%
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Gi0/2 Forwarding 50.00% 40.00% 0.00%
<output omitted>
Trunk(Native VLAN = 10)
Mitigating VLAN Attacks
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(Native VLAN = 10)
1. Disable trunking on all access ports.
2. Disable auto trunking and manually enable trunking
3. Be sure that the native VLAN is used only for trunk lines and no where else
switchport mode trunk
switchport nonegotiate
.
Switch(config-if)#
• Specifies an interface as a trunk link
Switch(config-if)#
Controlling Trunking
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switchport trunk native vlan vlan_number
switchport nonegotiate
• Prevents the generation of DTP frames.
Switch(config-if)#
• Set the native VLAN on the trunk to an unused VLAN
Traffic Analysis
� A SPAN port mirrors traffic to another port where a monitoring device is connected.
“Intruder Alert!”
IDSRMON ProbeProtocol Analyzer
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connected.
� Without this, it can be difficult to track hackers after they have entered the network.
Attacker
CLI Commands
monitor session session_number source {interfaceinterface-id [, | -] [both | rx | tx]} | {vlan vlan-
id [, | -] [both | rx | tx]}| {remote vlan vlan-id}
Switch(config)#
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monitor session session_number destination{interface interface-id [, | -] [encapsulation replicate] [ingress {dot1q vlan vlan-id | isl |
untagged vlan vlan-id | vlan vlan-id}]} | {remote vlan vlan-id}
Switch(config)#
Verify SPAN Configuration
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SPAN and IDS
IDS
Use SPAN to mirror traffic in and out of port F0/1
F0/2
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Attacker
and out of port F0/1 to port F0/2.
F0/1
Overview of RSPAN
• An RSPAN port mirrors traffic to another port on another switch where a probe or IDS sensor is connected.
• This allows more switches to be monitored with a single
“Intruder Alert!”
IDS
RSPAN VLAN
Source VLAN
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be monitored with a single probe or IDS.
Attacker
RSPAN VLAN
Source VLAN
Source VLAN
Configuring RSPAN
2960-1 2960-2
2960-1(config)# vlan 1002960-1(config-vlan)# remote-span2960-1(config-vlan)# exit
1. Configure the RPSAN VLAN
2. Configure the RSPAN source ports and VLANs
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2960-1(config)# monitor session 1 source interface FastEthernet 0/12960-1(config)# monitor session 1 destination remote vlan 100
reflector-port FastEthernet 0/242960-1(config)# interface FastEthernet 0/22960-1(config-if)# switchport mode trunk
2960-2(config)# monitor session 2 source remote vlan 1002960-2(config)# monitor session 2 destination interface FastEthernet 0/32960-2(config)# interface FastEthernet 0/22960-2(config-if)# switchport mode trunk
2. Configure the RSPAN source ports and VLANs
3. Configure the RSPAN traffic to be forwarded
Verifying RSPAN Configuration
2960-1 2960-2
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show monitor [session {session_number | all | local | range list | remote} [detail]] [ | {begin | exclude| include}expression]
Layer 2 Guidelines
• Manage switches in as secure a manner as possible (SSH, out-of-band management, ACLs, etc.)
• Set all user ports to non-trunking mode (except if using Cisco VoIP)
• Use port security where possible for access ports
• Enable STP attack mitigation (BPDU guard, root guard)
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• Enable STP attack mitigation (BPDU guard, root guard)
• Use Cisco Discovery Protocol only where necessary –with phones it is useful
• Configure PortFast on all non-trunking ports
• Configure root guard on STP root ports
• Configure BPDU guard on all non-trunking ports
VLAN Practices
• Always use a dedicated, unused native VLAN ID for trunk ports
• Do not use VLAN 1 for anything
• Disable all unused ports and put them in an unused VLAN
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VLAN
• Manually configure all trunk ports and disable DTP on trunk ports
• Configure all non-trunking ports with switchport mode access
Overview of Wireless, VoIP Security
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Wireless VoIP
Overview of SAN Security
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SAN
Infrastructure-Integrated Approach
• Proactive threat and intrusion detection capabilities that do not simply detect wireless attacks but prevent them
• Comprehensive protection to safeguard confidential data and
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safeguard confidential data and communications
• Simplified user management with a single user identity and policy
• Collaboration with wired security systems
Cisco IP Telephony Solutions
• Single-site deployment
• Centralized call processing with remote branches
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• Distributed call-processing deployment
• Clustering over the IPWAN
Storage Network Solutions
• Investment protection
• Virtualization
• Security
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• Security
• Consolidation
• Availability
Cisco Wireless LAN Controllers
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• Responsible for system-wide wireless LAN functions
• Work in conjunction with Aps and the Cisco Wireless Control System (WCS) to support wireless applications
• Smoothly integrate into existing enterprise networks
Wireless Hacking
• War driving
• A neighbor hacks into another neighbor’s wireless network to get free Internet access or
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free Internet access or access information
• Free Wi-Fi provides an opportunity to compromise the data of users
Hacking Tools
• Network Stumbler
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• Network Stumbler• Kismet• AirSnort• CoWPAtty• ASLEAP• Wireshark
Safety Considerations
• Wireless networks using WEP or WPA/TKIP are not very secure and vulnerable to hacking attacks.
• Wireless networks using WPA2/AES should
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• Wireless networks using WPA2/AES should have a passphrase of at least 21 characters long.
• If an IPsec VPN is available, use it on any public wireless LAN.
• If wireless access is not needed, disable the wireless radio or wireless NIC.
VoIP Business Advantages
• Little or no training costs
• Mo major set-up fees
PSTN VoIP
Gateway
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• Lower telecom call costs
• Productivity increases
• Lower costs to move, add, or change
• Lower ongoing service and maintenance costs
• Mo major set-up fees
• Enables unified messaging
• Encryption of voice calls is supported
• Fewer administrative personnel required
VoIP Components
Cisco UnifiedCommunications
Manager(Call Agent)
MCU
IPBackbone
PSTN
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CiscoUnity
IPPhone
IPPhone
VideoconferenceStation
Router/Gateway
Router/Gateway
Router/Gateway
VoIP Protocols
VoIP Protocol Description
H.323ITU standard protocol for interactive conferencing; evolved from H.320
ISDN standard; flexible, complex
MGCP Emerging IETF standard for PSTN gateway control; thin device control
Megaco/H.248Joint IETF and ITU standard for gateway control with support for multiple
gateway types; evolved from MGCP standard
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SIPIETF protocol for interactive and noninteractive conferencing; simpler but
less mature than H.323
RTPETF standard media-streaming protocol
RTCPIETF protocol that provides out-of-band control information for an RTP flow
SRTPIETF protocol that encrypts RTP traffic as it leaves the
voice device
SCCPCisco proprietary protocol used between Cisco Unified Communications
Manager and Cisco IP phones
Threats
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• Reconnaissance
• Directed attacks such as spam over IP telephony (SPIT) and spoofing
• DoS attacks such as DHCP starvation, flooding, and fuzzing
• Eavesdropping and man-in-the-middle attacks
VoIP SPIT
• If SPIT grows like spam, it could result in regular DoS problems for network administrators.
• Antispam methods do not block SPIT.
• Authenticated TLS stops most SPIT attacks because TLS endpoints accept packets only from trusted devices.
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only from trusted devices.
You’ve just won an all expenses
paid vacation to the U.S.
Virgin Islands !!!
Fraud
• Fraud takes several forms:
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– Vishing—A voice version of phishing that is used to compromise confidentiality.
– Theft and toll fraud—The stealing of telephone services.
• Use features of Cisco Unified Communications Manager to protect against fraud.
– Partitions limit what parts of the dial plan certain phones have access to.
– Dial plans filter control access to exploitive phone numbers.
– FACs prevent unauthorized calls and provide a mechanism for tracking.
SIP Vulnerabilities
• Registration hijacking: Allows a hacker to intercept incoming calls and reroute them.
• Message tampering: Allows a hacker to
Registrar RegistrarLocationDatabase
SIP Servers/Services
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Allows a hacker to modify data packets traveling between SIP addresses.
• Session tear-down:Allows a hacker to terminate calls or carry out VoIP-targeted DoS attacks.
SIP Proxy
SIP User Agents SIP User Agents
Using VLANs
Voice VLAN = 110 Data VLAN = 10
IP phone10.1.110.3
Desktop PC
5/1
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• Creates a separate broadcast domain for voice traffic• Protects against eavesdropping and tampering• Renders packet-sniffing tools less effective• Makes it easier to implement VACLs that are specific to voice
traffic
802.1Q Trunk 10.1.110.3Desktop PC
171.1.1.1
Using Cisco ASA AdaptiveSecurity Appliances
• Ensure SIP, SCCP, H.323, and MGCP requests conform to standards
• Prevent inappropriate SIP methods from being sent to Cisco Unified Communications Manager
• Rate limit SIP requests
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• Rate limit SIP requests
• Enforce policy of calls (whitelist, blacklist, caller/called party, SIP URI)
• Dynamically open ports for Cisco applications
• Enable only “registered phones” to make calls
• Enable inspection of encrypted phone calls
Internet
WAN
Cisco Adaptive Security Appliance
Cisco Adaptive Security Appliance
Using VPNs
• Use IPsec for authentication
• Use IPsec to protect all traffic, not just voice
• Consider SLA with service provider
• Terminate on a VPN concentrator
Telephony Servers
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• Terminate on a VPN concentrator or large router inside of firewall to gain these benefits:
• Performance
• Reduced configuration complexity
• Managed organizational boundaries
IP WAN
SRSTRouter
Using Cisco Unified Communications Manager
• Signed firmware
• Signed configuration files
• Disable:
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• Disable:
– PC port
– Setting button
– Speakerphone
– Web access
SAN Security Considerations
SAN IP
Network
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Specialized network that enables fast, reliable access among servers and external storage resources
SAN Transport Technologies
• Fibre Channel – the primary SAN transport for host-to-SAN connectivity
• iSCSI – maps SCSI over TCP/IP and is another
LAN
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TCP/IP and is another host-to-SAN connectivity model
• FCIP – a popular SAN-to-SAN connectivity model
World Wide Name
• A 64-bit address that Fibre Channel networks use to uniquely identify each element in a Fibre Channel network
• Zoning can utilize WWNs to assign security
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• Zoning can utilize WWNs to assign security permissions
• The WWN of a device is a user-configurable parameter.
Cisco MDS 9020 Fabric Switch
Zoning Operation
• Zone members see only other members of the zone.
• Zones can be configured dynamically based on WWN.
• Devices can be members of
SAN
Disk1Host1
Disk2 Disk3
ZoneAZoneC
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• Devices can be members of more than one zone.
• Switched fabric zoning can take place at the port or device level: based on physical switch port or based on device WWN or based on LUN ID.
Host2Disk4
ZoneB
An example of Zoning. Note that devices can be members of more than 1 zone.
Virtual Storage Area Network (VSAN)
Physical SAN islands are virtualized onto
Cisco MDS 9000Family with VSAN Service
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are virtualized onto common SAN infrastructure
Security Focus
SAN
Target AccessSAN Protocol
SAN Management Access
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SAN
SecureSAN
IP Storage access
Data Integrity and Secrecy
AccessFabric Access
SAN Management
Three main areas of vulnerability:
1. Disruption of switch processing
2. Compromised fabric stability
3. Compromised data integrity and confidentiality
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3. Compromised data integrity and confidentiality
Fabric and Target Access
Three main areas of focus:
• Application data integrity
• LUN integrity
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• Application performance
VSANs
Two VSANs each with multiple zones. Disks and hosts are dedicated to VSANs although both hosts
Physical Topology
VSAN 2
Disk1Host1
Disk2 Disk3
ZoneAZoneC
Relationship of VSANs to Zones
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VSANs although both hosts and disks can belong to multiple zones within a single VSAN. They cannot, however, span VSANs.
VSAN 3
Host2Disk4
Disk6
Disk5
Host4
Host3
ZoneB
ZoneA
ZoneD
iSCSI and FCIP
• iSCSI leverages many of the security features inherent in Ethernet and IP
– ACLs are like Fibre Channel zones
– VLANs are like Fibre Channel VSANs
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– 802.1X port security is like Fibre Channel port security
• FCIP security leverages many IP security features in Cisco IOS-based routers:
– IPsec VPN connections through public carriers
– High-speed encryption services in specialized hardware
– Can be run through a firewall
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