D-Link DGS-3324SRi Intelligent Stackable Gigabit Ethernet Switch
96
IP Address
The IP address corresponding to the Interface Name showing in the field
above.
TX Mode <
Disabled
>
Toggle among
Disabled
,
v1 Only
,
v1 Compatible
, and v
2 Only
. This entry
specifies which version of the RIP protocol will be used to transmit RIP
packets.
Disabled
prevents the transmission of RIP packets.
RX Mode <
Disabled
>
Toggle among
Disabled
,
v1 Only
,
v2 Only
, and
v1 or v2
. This entry
specifies which version of the RIP protocol will be used to interpret
received RIP packets.
Disabled
prevents the reception of RIP packets.
Authentication
Toggle between
Disabled
and
Enabled
to specify that routers on the
network should us the Password above to authenticate router table
exchanges.
Password
A password to be used to authenticate communication between routers on
the network.
State
Toggle between
Disabled
and
Enabled
to disable or enable this RIP
interface on the switch.
Interface Metric
A read only field that denotes the Metric value of the current IP Interface
setting.
Configuring OSPF
OSPF Authentication
OSPF packets can be authenticated as coming from trusted routers by the use of predefined passwords. The
default for routers is to use not authentication.
There are two other authentication methods
−
simple password authentication (key) and Message Digest
authentication (MD-5).
Message Digest Authentication (MD-5)
MD-5 authentication is a cryptographic method. A key and a key-ID are configured on each router. The router
then uses an algorithm to generate a mathematical “message digest” that is derived from the OSPF packet, the
key and the key-ID. This message digest (a number) is then appended to the packet. The key is not exchanged
over the wire and a non-decreasing sequence number is included to prevent replay attacks.
Simple Password Authentication
A password (or key) can be configured on a per-area basis. Routers in the same area that participate in the
routing domain must be configured with the same key. This method is possibly vulnerable to passive attacks
where a link analyzer is used to obtain the password.
The Backbone and Area 0
OSPF limits the number of link-state updates required between routers by defining areas within which a given
router operates. When more than one area is configured, one area is designated as area 0
−
also called the
backbone.
The backbone is at the center of all other areas
−
all areas of the network have a physical (or virtual) connection
to the backbone through a router. OSPF allows routing information to be distributed by forwarding it into area 0,
from which the information can be forwarded to all other areas (and all other routers) on the network.
In situations where an area is required, but is not possible to provide a physical connection to the backbone, a
virtual link can be configured.
Virtual Links
Virtual links accomplish two purposes: