Discussion

Table 9-4. Actions that change routing information in matching routes (continued)
Action term
external type metric
local-preference value
local-preference add number
local-preference subtract number
metric value
metric2 value
metric igp value
metric minimum-igp value
origin value
preference value
tag value
tag2 value
tag add number
tag subtract number
tag2 add number
tag2 subtract number
Description
External metric for exported OSPF routes.
Set the value of the BGP LOCAL_PREF attribute.
Increment or decrement the BGP LOCAL_PREF value.
Set the metric value. For BGP, metric is MED and metric2 is the IGP
metric of the BGP next hop.
Change the MED by the specified value for EBGP routes being exported.
Set the BGP ORIGIN attribute.
Set the preference value.
Set the tag and tag2 values in OSPF external LSAs.
Increment or decrement the OSPF tag or tag2 value.
This recipe changes two attributes in a BGP route, the local preference and community.
The first command in the then clause sets the LOCAL_PREF attribute to 300.
The second command changes the community string in the route to 65500:12345.
The policy affects all routes received from the BGP neighbor at 10.0.31.2/32 (configured
with the set from neighbor command). The last command in the recipe applies
the policy to the BGP group external.
9.3 Filtering Routes by IP Address
Problem
You need to reject all routes to certain IP addresses because you don’t want to install
them into the routing table.
Solution
Create a list of all the IP address prefixes:
[edit policy-options]
aviva@router1# set prefix-list PREFIX-LIST-1 10.0.0.1/24
aviva@router1# set prefix-list PREFIX-LIST-1 10.10.0.0/16
aviva@router1# show
prefix-list PREFIX-LIST-1 {
10.0.0.1/24;
10.10.0.0/16;
}
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