Riverbed SteelHead 3070-SD, User Manual

Page: 58 / 124

58 | Configuring BGP, OSPF, Static Routing, and Route Retraction on SteelHead SD
Configuring OSPF with ABR on SteelHead SD
Click Off to define unique settings for the network and to lock the network configuration so any
changes do not overwrite the settings.
• Password - Specify a password. The authentication methods appear when typing a password. All
OSPFv2 exchanges between routing devices can be authenticated using one of these methods:
– MD5 - Select this tab to use the Message Digest 5 algorithm as the authentication method. MD5
authentication enables routing devices to securely identify one another before they establish
adjacency. MD5 is a cryptographic hash function with a 128-bit hash value derived from the
contents of the OSPF packet and a key and key ID. This method doesn’t send the password but
instead calculates and includes an encoded MD5 checksum in the transmitted packet. The
receiving routing device uses the key and key ID to verify the packet.
The MD5 key doesn’t have to be the same within the area, but it must be exactly the same
between two OSPF neighbors.
Tip: Click the eye icon to see the password as you type. The view persists until you click the eye icon again to hide
the password.
– Simple - Select this tab to include an unencrypted plain text password with the packet. The
receiving routing device uses the password to verify the packet. The simple password can be
from one to eight characters and can include ASCII strings. If you include spaces, enclose the
password in quotation marks. Use this authentication method when devices within an area do
not support the more secure MD5 authentication, as Simple is the least secure setting.
• MD5 Key ID - (Appears when you select MD5.) Specify a value to associate with the MD5 key. The ID
is used by the receiver of the OSPF packet to determine which key to use for authentication.
To change your MD5 key, specify a new key and key ID. When both OSPF neighbors have a new key
and key ID, the old key is deleted and the current MD5 key and key ID become active.
• Hello Interval - Specify how often, in seconds, to send a hello packet. Initially the gateway sends a
hello packet to all OSPF-enabled interfaces to form an adjacency as a neighbor. The routing devices
become neighbors and exchange link-state advertisements. After the gateway learns the common
network topology, it sends the hello to check if an OSPF neighbor is alive. The range is from 1 to
65535. The default is 10. The hello interval must be exactly the same between two OSPF neighbors.
• Dead Interval - Specify how many seconds to wait for a hello packet before declaring an OSPF
neighbor out of service, triggering a refresh of the link-state database and routing information. The
range is from 1 to 65535. The default is 40. The dead interval must be exactly the same between two
OSPF neighbors.
• Priority - Specify the priority for becoming the network’s designated routing device. The designated
router originates network link advertisements on behalf of the network, and it establishes
adjacencies with all routing devices on the network.
The routing device that has the highest priority value on the logical IP network or subnet is elected
as the designated router. A priority value of 0 means that the routing device never becomes the
designated router; it doesn’t even participate in the election process. A value of 1 means that the
routing device participates in the election process but has the least chance of becoming a
designated router. A priority of 255 means the routing device is always the designated router.