Cisco's ASA55xx series are adaptive security appliances that provide firewall, IPSec and SSL VPN capabilities. The appliances range from small office/home office models like the ASA550x to data center models like the ASA558x. All models support stateful packet inspection firewalls and VPN endpoints. Optional modules allow for intrusion prevention, content filtering, and additional network interfaces. Licenses determine the number of supported VPN connections and interfaces/VLANs.
4. Firewall
• Default firewall rules
– Outbound traffic is allowed unless otherwise
specified
– Inbound traffic is denied unless otherwise
specified
• Stateful packet inspection ensures that
responses to outbound traffic match outgoing
requests
5. ASA Firewall
• ASA assigns a security level to each interface
– inside is 100, outside (Interent) is 0, DMZ is
typically assigned 50
– Default rules allow free flow from higher security
level to lower security 0 level
• NAT/PAT
– Allows for more servers with fewer public Ips
• Deep packet inspection
6. IPSec VPN
• Used for LAN-to-LAN connections
• Workstation clients for Windows, Macintosh,
Linux
• Maximum connections depends on model
• No additional licenses required
• EasyVPN
– Simplified configuration
– Inbound connections only
7. SSL VPN
• No pre-installed client – connect with web
browser
• Licensed by simultaneous connections (2
connections permitted for testing)
• Clientless connection
– Simplest configuration
– Limited to web applications
– Some client-server applications are SSL VPN aware
8. SSL VPN
• Cisco AnyConnect VPN client
• Downloaded on-the-fly
• Full network access (if desired)
• Windows/Macintosh/Linux
• May not function of user rights on client
computer limited
9. IPSec vs SSL
IPSec
• Workstation configuration
required
• Administrator can configure
VPN then restrict user
access
• Access as if client machine
on LAN
• Has pre-shared key in
addition to user password
• No additional cost
SSL
• Browser-based from any
computer
• Limited access if user does
not have right to install
applications
• Need to use web applictions
to ensure access
• Vulnerable to password
compromise
• Extra cost feature
11. ASA550x – Base License
• 10/50/Unlimited internal devices
• 10 Simultaneous VPNs
• 8 10/100 Ethernet ports – assigned to VLANs
• 2 Power over Ethernet
• 3 VLANs
• One VLAN must be isolated from
communicating with one of the others.
13. ASA550x – Security Plus
• 25 Simultaneous VPNs
• Ports must be assigned to one of three
interfaces, up to 20 trunked VLANs permitted
• Communications between interfaces restriced
by standard firewall rules
• Failover to backup ISP for outbound access
14. ASA551x – Base License
• 250 Simultaneous VPNs
• 3 – 10/100 Ethernet ports – Firewall interfaces
• 1 – 10/100 Ethernet port – Management only
• Up to 50 Trunked VLANs
• SSM Slot for Content Filter or Intrusion
Prevention Module
15. ASA551x – Security Plus License
• 250 Simultaneous VPNs
• 3 – 10/100 Ethernet ports
• 2 – 10/100/1000 Ethernet ports
• Up to 100 Trunked VLANs
• SSM Slot for Content Filter, Intrusion
Prevention Module, or 4 x 10/100/1000
Ethernet Port module
• 2 included/5 maximum Security Contexts
16. ASA552x
• 750 Simultaneous VPNs
• 1 – 10/100 Ethernet port
• 4 – 10/100/1000 Ethernet ports
• Up to 150 Trunked VLANs
• SSM Slot for Content Filter, Intrusion
Prevention Module, or 4 x 10/100/1000
Ethernet Port module
• 2 included/20 maximum Security Contexts
17. ASA554x
• 5000 Simultaneous VPNs (2500 SSL)
• 1 – 10/100 Ethernet port
• 4 – 10/100/1000 Ethernet ports
• Up to 200 Trunked VLANs
• SSM Slot for Content Filter, Intrusion
Prevention Module, or 4 x 10/100/1000
Ethernet Port module
• 2 included/50 maximum Security Contexts
18. ASA555x
• 5000 Simultaneous VPNs
• 1 – 10/100 Ethernet port
• 4 – 10/100/1000 Ethernet ports
• 4 ports selectable 1000T/SFP Fiber ports
• Up to 250 Trunked VLANs
• No SSM Slot
• 2 included/50 maximum Security Contexts
19. Content Security and Control Module
• Standard License
– Anti-virus
– Anti-Spyware
– File blocking
• Plus License adds
– Anti-SPAM
– URL Filter
– E-mail content control
20. Content Security and Control Module
• CSC-SSM-10
– 50/100/250/500 users
– ASA5510 and ASA5520
• CSC-SSM-20
– 750/1000 users
– ASA5510 , ASA5520, ASA5540
• Subscription required for updates
21. Advanced Intrusion Prevention
• Compares every packet against a signature
database
• Alerting or automatic blocking
• Update subscription required
Notas del editor
ASA is a stateful packet inspection firewall. Some protocols are inspected at a other layers
Anti-X – anti-virus, anti-spy, file filter, anti-spam, url filter
Stateful packet inspection has been standard for ALMOST 10 years, some early low-cost NAT devices lacked it.
Typical firewalls allow for one of each type of server on a single pubic IP. Multiple Ips must be assigned one to one to internal servers. PAT allows for one server per protocol per public IP. Not exclusive to Cisco, but not typically found on low end fuirewalls.
Deep packet inspection performs basic checks for validity on some protocols.