Nera SatLink 1000, User Manual

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Nera SatLink Terminal User Guide – Revision P
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Please note that translation of outbound TCP/UDP fragmented datagrams will fail with NAT enabled. The
reason is that only the first fragment contains the TCP/UDP header that would be necessary to associate
the packet to a session for translation purposes. Subsequent fragments do not contain TCP/UDP port
information, but simply carry the same fragmentation identifier specified in the first fragment.
Consequently the sessions will be corrupted. Whether NAT drops or forwards also an ICMP fragmented
packets depends on a number of things, such as the order in which the NAT router receives the ICMP
fragments, and the state of the translation table at that time. Under certain conditions, NAT translates the
ICMP fragments differently, making it impossible for the destination device to reassemble the packet.
To view the currently configured dynamic NAPT entries, type the CLI command:
# ip nat show.
Example:
# ip nat global add 10.10.1.10
# ip nat show
NAT Configuration
-----------------
Network Address Port Translation (NAPT): Enabled
Global Address Table
If IP Address
dvb0 10.10.1.10
NAT Status
----------
Total Sessions 0
Active Sessions 0
Failed Sessions 0
Packet Translations 0
13.1.2 Configuration of Static NAPT
Static NAPT is used to map incoming connections to different local hosts dependent on their TCP/UDP
port number.
When using static NAPT, both the IP addresses and port numbers of the incoming packets will be
substituted with the IP addresses and port numbers that defined using the CLI command:
# ip nat napt add <gladdr> <glport> <locaddr> [<locport>]
.
Multiple global address/port combinations can be mapped to the same local address/port.
Static NAPT entries in the address translation table are removed by issuing the CLI command:
# ip nat napt del <gladdr> <glport>
To view the currently configured static NAPT entries, type the CLI command:
# ip nat show