Cisco ASA 5505 Configuration Manual page 402

Customizing OSPF
Choose Advanced to edit advanced virtual link properties,
Step 6
The Advanced OSPF Virtual Link Properties dialog box appears. You can configure the OSPF properties
for the virtual link in this area. These properties include authentication and packet interval settings
In the Authentication area, choose the Authentication type by clicking the radio button next to your
Step 7
choice. OSPF authentication options include:
• None—Choose this option to disable OSPF authentication.
• Authentication Password—Choose this option to use clear text password authentication. This is
not recommended where security is a concern.
• MD5—Choose this option to use MD5 authentication (recommended).
• Area—(Default) Choose this option to use the authentication type specified for the area (see the
"Configuring OSPF Area Parameters" section on page 21-12
authentication). Area authentication is disabled by default. So, unless you have previously specified
an area authentication type, interfaces set to area authentication have authentication disabled until
you configure area authentication.
In the Authentication Password area enter and re-enter a password when password authentication is
Step 8
enabled from Step 7. Passwords must be a text string of up to 8 characters.
In the MD5 IDs and Keys area, enter the MD5 keys and parameters when MD5 authentication is enabled
Step 9
from Step 7. All devices on the interface using OSPF authentication must use the same MD5 key and ID.
Fields include:
• Key ID—Enter a numerical key identifier. Valid values range from 1 to 255. This field also displays
the Key ID for the interface selected.
Key—An alphanumeric character string of up to 16 bytes. This field also displays the Key ID for the
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interface selected.
Click the Add or Delete button to add or delete the specified MD5 key to the MD5 ID and Key table.
In the Interval area, choose the interval timing for the packet by choosing from the following options:
Step 10
Hello Interval—Specifies the interval, in seconds, between hello packets sent on an interface. The
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smaller the hello interval, the faster topological changes are detected but the more traffic is sent on
the interface. This value must be the same for all routers and access servers on a specific interface.
Valid values range from 1 to 65535 seconds. The default value is 10 seconds.
Retransmit Interval—Specifies the time, in seconds, between LSA retransmissions for adjacencies
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belonging to the interface. When a router sends an LSA to its neighbor, it keeps the LSA until it
receives the acknowledgement message. If the router receives no acknowledgement, it will resend
the LSA. Be conservative when setting this value, or needless retransmission can result. The value
should be larger for serial lines and virtual links. Valid values range from 1 to 65535 seconds. The
default value is 5 seconds.
Transmit Delay—Specifies the estimated time, in seconds, required to send an LSA packet on the
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interface. LSAs in the update packet have their ages increased by the amount specified by this field
before transmission. If the delay is not added before transmission over a link, the time in which the
LSA propagates over the link is not considered. The value assigned should take into account the
transmission and propagation delays for the interface. This setting has more significance on very
low-speed links. Valid values range from 1 to 65535 seconds. The default value is 1 second.
Dead Interval—Specifies the interval, in seconds, in which no hello packets are received, causing
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neighbors to declare a router down. Valid values range from 1 to 65535. The default value of this
field is four times the interval set by the Hello Interval field.
Cisco ASA 5500 Series Configuration Guide using ASDM
21-18
Chapter 21 Configuring OSPF
for information about configuring area
OL-20339-01