Sidewinder G2 6.1.2 Administration Guide - Glossary of Technical ...

Figure 240: Sidewinder
G2 within OSPF area 0
backbone
Figure 241: Sidewinder
G2 within OSPF area “n”
Appendix C: Configuring Dynamic Routing with OSPF
OSPF processing on a Sidewinder G2
Sidewinder G2 in an OSPF network topology
Essentially there are two choices for locating the Sidewinder G2 within the
OSPF network topology.
• the Sidewinder G2 within OSPF area 0 backbone
• the Sidewinder G2 within OSPF area n
The first choice, shown in Figure 240, extends the AS backbone through the
Sidewinder G2. Any area boundary external is to the Sidewinder G2.
area 0 (backbone)
Complicated
Network
b
u
r
b
area n (8.8.8.8)
The second choice, shown in Figure 241, runs a non-backbone area through
the Sidewinder G2, placing the backbone completely internal. This second
option is preferable for security policy reasons, but may not be practical without
re-engineering the OSPF network.
area 0 (backbone)
Complicated
Network
Autonomous system (AS)
b
u
r
b
Sidewinder G2
R
ABR
Autonomous system (AS)
R
ABR
Network
area n (8.8.8.8)
Sidewinder G2
ASBR
In order for OSPF to work, it is important that all routers work off of a consistent
link state database. The Sidewinder G2 implementation allows a customer to
control which routers it will communicate with by using the rule list. The active
rule list can be configured to only allow known routers to talk to gated.
b
u
r
b
b
u
r
R
b ASBR
R
605