Provider Communities (XRv)

Topology: bgp-mh-xr

configure
load bootflash:communities.init.cfg
commit r
y

This lab is the same as the previous "Provider Communities" lab, just with XRv nodes instead of IOL nodes.

• All links are in the format 100.X.Y.X/24.

  • For example, the link between R4 and R7 is 100.4.7.0/24.

• Lo0 is X.X.X.X/32 and is used for iBGP

• Lo1 is <AS>.0.0.X/32 and is used as a public IP address that is pingable. The public Lo1 addresses are aggregated into a /8 at each edge router.

• eBGP and iBGP is fully preconfigured.

Configure communities in AS20 to accomplish the following:

• AS10 is an upstream provider, AS40 is a transit peer, and AS50 is a customer. Only advertise customer and local routes to transit peers and providers. Do not let transit routes leak to upstream providers, and upstream routes leak to transit providers.

• Allow AS50 to control their inbound traffic using the following table:

Community	Action
20:80	LP=80
20:90	LP=90
20:110	LP=110
20:120	LP=120
20:1	Prepend AS20 one additional time on advertisements to upstreams
20:2	Prepend AS20 two additional times on advertisements to upstreams
20:3	Prepend AS20 three additional times on advertisements to upstreams

Answer

#R2, R4, R5
route-policy TAG_FOR_EXPORT
 set community (20:1000)
end-policy
!
router bgp 20
 add ipv4 uni
  network 20.0.0.0/8 route-policy TAG_FOR_EXPORT
!
route-policy TRANSIT_OUTBOUND
 if community matches-any (20:1000) then pass endif
end-policy
!
route-policy UPSTREAM_PREPEND
 if community matches-any (20:1) then
  prepend as-path own-as 1
 endif
 if community matches-any (20:2) then
  prepend as-path own-as 2
 endif
 if community matches-any (20:3) then
  prepend as-path own-as 3
 endif
end-policy
!
route-policy UPSTREAM_OUTBOUND
 if community matches-any (20:1000) then
  apply UPSTREAM_PREPEND
  pass
 else
  drop
 endif
end-policy
!
route-policy CUSTOMER_INBOUND
 if community matches-any (20:80) then
  set local-preference 80
 endif
 if community matches-any (20:90) then
  set local-preference 90
 endif
 if community matches-any (20:110) then
  set local-preference 110
 endif
 if community matches-any (20:120) then
  set local-preference 120
 endif
 set community (20:1000) additive
end-policy


#R2
router bgp 20
 neighbor 100.1.2.1
  address-family ipv4 unicast
   route-policy UPSTREAM_OUTBOUND out
  !
 !
 neighbor 100.2.10.10
  address-family ipv4 unicast
   route-policy TRANSIT_OUTBOUND out


#R4
router bgp 20
 neighbor 100.4.7.7
  address-family ipv4 unicast
   route-policy CUSTOMER_INBOUND in


#R5
router bgp 20
 neighbor 100.5.8.8
  address-family ipv4 unicast
   route-policy CUSTOMER_INBOUND in

Verification is the same as the previous lab which uses IOL nodes.