Allied Telesis AT-8550 - Manual (Page 213)

AT-9108, AT-8518, AT-8525, and AT-8550 User’s Guide
12-5
This configuration results in the switch having no route back to the
VLAN Sales.
Access Policies
for OSPF
Because OSPF is a link-state protocol, the access policies associated
with OSPF are different in nature than those associated with RIP.
Access policies for OSPF are intended to extend the existing filtering
and security capabilities of OSPF (for example, link authentication
and the use of IP address ranges). If the OSPF protocol is being used,
the switch can be configured to use an access profile to determine
any of the following:
❑ Inter-area Filter — For switches configured to support
multiple OSPF areas (an ABR function), an access profile can be
applied to an OSPF area that filters a set of OSPF inter-area
routes from being sourced from any other areas. To configure
an inter-area filter policy, use the following command:
config ospf area interarea-
filter [ | none]
❑ External Filter — For switches configured to support
multiple OSPF areas (an ABR function), an access profile can be
applied to an OSPF area that filters a set of OSPF external
routes from being advertised into that area. To configure an
external filter policy, use the following command:
config ospf area external-
filter [ | none]
Note
If any of the external routes specified in the filter have already been
advertised, those routes will remain until the associated LSAs in that
area time-out.
❑ ASBR Filter — For switches configured to support route re-
distribution into OSPF, (an ASBR function), an access profile
can be used to limit the routes that are advertised into OSPF
for the switch as a whole. To configure an ASBR filter policy,
use the following command:
config ospf asbr-filter
[ | none]