Filtering Routes By Router; Filtering Routes Using Nlri - Zte ZXR10 5900E Series User Manual

St-
Command
ep
1
route-map <map-tag>[permit|den
ZXR10(config)#
y][<sequence-number>]
2
ZXR10(config-router)#
route-map <map-tag>{in|out}
Example
Example

Filtering Routes by Router

Route filtering and attributes are the basis of BGP decision. Route
filtering allows controlling the attributes of the imported and ex-
ported routes based on needs.
Route map is used to control the routing information and redis-
tribute routes between areas by defining conditions. Route map
usually works with route attributes to allow making decisions on
routes.
neighbor <ip-address>
To configure routes filtering by routers, an example is given below:
ZXR10_R1(config)#router bgp 100
ZXR10_R1(config-router)#neighbor 182.17.20.1 remote-as 200
ZXR10_R1(config-router)#neighbor 182.17.20.1 route-map MAP1 out
ZXR10_R1(config-router)#neighbor 182.17.20.1 send-med
ZXR10_R1(config-router)#exit
ZXR10_R1(config)#route-map MAP1 permit 10
ZXR10_R1(config-route-map)#match ip address 1
ZXR10_R1(config-route-map)#set metric 5
ZXR10_R1(config-route-map)#exit
ZXR10_R1(config)#acl standard number 1
ZXR10_R1(config-std-acl)#rule 1 permit 172.3.0.0 0.0.255.255
MAP1 is a router defined in above example. Its route map allows
the network 172.3.0.0 to be advertised to AS 200 and sets its MED
to 5. The route map is often used with match and set command.
Match command defines the match conditions. Set command de-
fines action to be executed when match conditions are met by
match command.

Filtering Routes Using NLRI

To set limit to a router when it gets or advertises the routing infor-
mation. The route updates can be filtered from or destined for a
particular neighbor. The filter has an update list of the neighbors
where the route updates are from or destined for.
R1 and R2 are IBGP peers. R1 and R3 are EBGP peers. R2 and R4
are EBGP peers. This is shown in
Confidential and Proprietary Information of ZTE CORPORATION
Chapter 5 BGP Configuration
Function
This defines a route map
This filters the routes
advertised or being advertised
to neighbors.
Figure 17.
51