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Supported RADIUS Attribute/
Value Pairs for L2TP operation
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F.9.3. IP over LCP
IP over LCP is a non standard coding of PPP packets for IPv4 and IPv6. The coding uses the LCP code (C021)
instead of the IPv4 (0021) or IPv6 (0057) code. The first byte which would normally be the LCP type is 0x4X
(IPv4) or 0x6X (IPv6). The FireBrick assumes any such LCP codes are IPv4/IPv6 when received, and using a
RADIUS response can send IP packets using LCP. This is specifically to bypass any carrier IP specific shaping
or DPI.
F.9.4. Closed User Group
Each session can have a CUG defined (1-32768) which may be allow or restrict. Interfaces (port/VLAN) may
also be defined in the same way. A packet from an interface/session with a CUG is tagged with that packet. If
the source is restricted that packet can only leave via an interface/session with the same CUG. Similarly if the
target interface/session is restricted than only a packet tagged with the same CUG can be sent to it.
F.9.5. Routing table
The FireBrick operates independent routing cores allowing a totally independent routing table to be used for
L2TP wrapper traffic and payload traffic. It is also possible to set the payload table in use on a per session basis
from RADIUS thus allowing a walled garden to be set up, or a private network, or simple an unusable session.