59-5

Cisco ASA 5500 Series Configuration Guide using ASDM
Chapter59 Configuring the Botnet Traffic Filter
Information About the Botnet Traffic Filter
How the Botnet Traffic Filter Works

Figure 59-1 shows how the Botnet Traffic Filter works with the dynamic database plus DNS inspection

with Botnet Traffic Filter snooping.

Figure59-1 How the Botnet Traffic Filter Works with the Dynamic Database

ASA 5550 40,000

ASA 5580 100,000

Table59-1 DNS Reverse Lookup Cache Entries per Model

ASA Model Maximum Entries

Security Appliance
DNS
Reverse
Lookup Cache
Infected
Host
Malware Home Site
209.165.201.3
Syslog Server
Dynamic
Database DNS Server
DNS Snoop
1 DNS Request:
bad.example.com
3Connection to:
209.165.201.3
2 DNS Reply:
209.165.201.3
Internet
Botnet Traffic
Filter
3b. Send
Syslog Message/Drop Traffic
1a. Match?
3a. Match?
2a. Add
248631