Sql*Net Inspection - Cisco FirePOWER ASA 5500 series Configuration Manual

Chapter 25 Configuring Application Layer Protocol Inspection
hostname(config-snmp-map)# deny version 2

SQL*Net Inspection

SQL*Net inspection is enabled by default.
The SQL*Net protocol consists of different packet types that the security appliance handles to make the
data stream appear consistent to the Oracle applications on either side of the security appliance.
The default port assignment for SQL*Net is 1521. This is the value used by Oracle for SQL*Net, but
this value does not agree with IANA port assignments for Structured Query Language (SQL). Use the
class-map command to apply SQL*Net inspection to a range of port numbers.
The security appliance translates all addresses and looks in the packets for all embedded ports to open
for SQL*Net Version 1.
For SQL*Net Version 2, all DATA or REDIRECT packets that immediately follow REDIRECT packets
with a zero data length will be fixed up.
The packets that need fix-up contain embedded host/port addresses in the following format:
(ADDRESS=(PROTOCOL=tcp)(DEV=6)(HOST=a.b.c.d)(PORT=a))
SQL*Net Version 2 TNSFrame types (Connect, Accept, Refuse, Resend, and Marker) will not be
scanned for addresses to NAT nor will inspection open dynamic connections for any embedded ports in
the packet.
SQL*Net Version 2 TNSFrames, Redirect, and Data packets will be scanned for ports to open and
addresses to NAT, if preceded by a REDIRECT TNSFrame type with a zero data length for the payload.
When the Redirect message with data length zero passes through the security appliance, a flag will be
set in the connection data structure to expect the Data or Redirect message that follows to be translated
and ports to be dynamically opened. If one of the TNS frames in the preceding paragraph arrive after the
Redirect message, the flag will be reset.
The SQL*Net inspection engine will recalculate the checksum, change IP, TCP lengths, and readjust
Sequence Numbers and Acknowledgment Numbers using the delta of the length of the new and old
message.
SQL*Net Version 1 is assumed for all other cases. TNSFrame types (Connect, Accept, Refuse, Resend,
Marker, Redirect, and Data) and all packets will be scanned for ports and addresses. Addresses will be
translated and port connections will be opened.
Sun RPC Inspection
This section describes Sun RPC application inspection. This section includes the following topics:
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OL-10088-01
Sun RPC Inspection Overview, page 25-74
Managing Sun RPC Services, page 25-74
Verifying and Monitoring Sun RPC Inspection, page 25-75
Cisco Security Appliance Command Line Configuration Guide
SQL*Net Inspection
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