ND SatCom SKYWAN IDU 7000, Manual

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114 Network Design and Engineering Guide 2010-10-26
Data Networking
SkyWAN
®
Internet Protocol Features
4.2.4 Dynamic Routing with OSPF
Besides static IP routing the Sky WAN
®
IDU supports the dynamic routing protocol ’Open Short-
est Path First’ (OSPF) Version 2, as specified in RFC 2328.
In general dynamic routing messages create a higher protocol overhead. But if the routing to-
pology is static, OSPF messages do not create a high load on the network. As advantage of
OSPF, changes in the topology (e.g. due to link outages) are quickly and efficiently distributed
in the network, leading to a rapid rerouting of user traffic if that is possible.
The Sky WAN
®
IDU OSPF implementation has the following limitations:
- OSPF virtual links are not supported.
- Cryptographic router identification is not supported.
- Satellite interfaces may not belong to different OSPF areas.
The following OSPF features are available on Sky WAN
®
stations:
- Ethernet and satellite IP interfaces may be defined as ’broadcast’ OSPF interfaces.
- Single or multiple OSPF Areas.
- Up to 6 OSPF neighbors are possible on the Ethernet interface.
- Up to 200 OSPF neighbors are possible on the satellite interfaces.
- Up to 2400 link state advertisements can be stored.
- Up to 1200 dynamic routes can be stored in the routing table.
Redistribution of Static Routes via OSPF
This feature allows a combination of static and dynamic routing without the need to define and
maintain static routes on every network router. To distribute locally defined static routes by
OSPF to other routers the
Sky WAN
®
IDU has to be configured as Autonomous System Bound-
ary Router.
It is possible to suppress the redistribution of individual static routes through a filter mechanism.