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Nokia Network Voyager for IPSO 4.0 Reference Guide 447
Note
By default, all routes originating from the configures ASes are accepted.
You can accept or reject all routes from a particular AS by enabling the accept or restrict option
next to the All BGP routes from AS field.
1. You also can accept or reject particular routes from AS 100 by specifying a route filter.
Route filters are specified as shown in the Route Redistribution section. Assume that you
want to filter all routes that are strictly more specific than
10.0.0.0/8. In other words,
allow all routes whose prefix is not
10.0.0.0/8 except for 10.0.0.0/8 itself, but exclude
all routes that are more specific, such as
10.0.0.0/9 and 10.128.0.0/9.
2. To configure this filter, enter
10.0.0.0 in New IP prefix to import text box, and 8 in Mask
Length text box; click Apply.
3. Select Refines in the Match type drop-down list.
This specifies routes that are strictly more specific than
10.0.0.0/8.
4. Finally, click Restrict in the Action field.
This specifies discard the routes that match this prefix.
5. Click Apply.
The filter is fully configured.
To configure route inbound policy on Nokia Platform D based on ASPATH regular
expressions
1. Click Inbound Route Filters under Configuration > Routing in the tree view.
2. Click the Based on ASPATH Regular Expressions link.
3. Enter
500 in the Import ID edit box.
The import ID specifies the order in which the import lists are applied to each route. For
route filters based on AS path regular expressions, the range of values is from 1 to 511.
4. Enter a regular expression that identifies a set of ASes that should be matched with the
SPATH sequence of the route:
100|200
This sequence accepts all routes whose ASPATH sequence contains 100 or 200 or both.
5. Select one of the origin options from the Origin drop-down list; then click Apply.
These options detail the completeness of AS path information. An origin of IGP indicates
that an interior routing protocol-learned route was learned from an interior routing protocol
and is most likely complete. An origin of EGP indicates the route was learned from an
exterior routing protocol that does not support AS paths, and the path is most likely
incomplete. When the path information is incomplete, an origin of incomplete is used.
6. Enter a new route filter. In this example assume that you want to filter all routes that are
strictly more specific than
10.0.0.0/8. In other words, allow all routes whose prefix is not
10.0.0.0/8 except for 10.0.0.0/8 itself, but exclude all routes that are more specific,
such as
10.0.0.0/9 and 10.128.0.0/9.