Cisco 5505 - ASA Firewall Edition Bundle, Cli Configuration Manual

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1-6
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Inspection for Voice and Video Protocols
H.323 Inspection
•
Only static NAT is fully supported. Static PAT may not properly translate IP addresses embedded in
optional fields within H.323 messages. If you experience this kind of problem, do not use static PAT
with H.323.
•
Not supported with dynamic NAT or PAT.
•
Not supported with extended PAT.
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Not supported with NAT between same-security-level interfaces.
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Not supported with outside NAT.
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Not supported with NAT64.
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When a NetMeeting client registers with an H.323 gatekeeper and tries to call an H.323 gateway that
is also registered with the H.323 gatekeeper, the connection is established but no voice is heard in
either direction. This problem is unrelated to the ASA.
•
If you configure a network static address where the network static address is the same as a
third-party netmask and address, then any outbound H.323 connection fails.
•
Configuring both H.323 inspection and communication in and out of the same interface (using the
same-security-traffic permit intra-interface command) on the ASA is not supported. When you
configure both these features, the ASA cannot correctly establish NetMeeting calls because it
modifies the H.225 setup message incorrectly by changing the destCallSignalAddress field to point
to itself rather than the NetMeeting destination endpoint.
To workaround this limitation, perform one of the following actions:
–
Configure the ASA so that either H.323 inspection or communication in and out of the same
interface, but not both, is set up on the device.
To disable communication on the same interface, remove the same-security-traffic permit
intra-interface command.
To disable H.323 inspection, enter the no inspect h323 h225 command under the global policy.
–
Configure inside to inside traffic to use NAT 0:
access-list id permit ip src_ip mask dest_ip mask
Where
src_ip mask
and
dest_ip mask
are both the inside network.
Configuring an H.323 Inspection Policy Map for Additional Inspection
Control
To specify actions when a message violates a parameter, create an H.323 inspection policy map. You can
then apply the inspection policy map when you enable H.323 inspection.
To create an H.323 inspection policy map, perform the following steps:
Step 1
(Optional) Add one or more regular expressions for use in traffic matching commands according to the
“Creating a Regular Expression” section on page 1-14 . See the types of text you can match in the match
commands described in Step 3 .
Step 2
(Optional) Create one or more regular expression class maps to group regular expressions according to
the
“Creating a Regular Expression Class Map” section on page 1-17 .s
Step 3
(Optional) Create an H.323 inspection class map by performing the following steps.