RS BGP configuration

Please make sure you only announce what you own and what your downstream have ask you to announce. If your network policy permits you should not filter any prefixes from CNX and you should prioritize traffic routes using CNX – remember whatever goes through this port is free traffic for your network and the fastest route for your customer. If you have downstream peers also peering at CNX you may want to filter those routes as to not conflict with your business routes.

Please read our documentation on route and ASN filtering to make sure our RS will accept your advertised routes

• prefix filtering
• ASN filtering

IPv4 peering Cisco

Example Cisco configuration for peering with CNX Route Server, replace 10.1.0.0/16 with your prefix delegation.

Note that for IOS versions after 12.2 you have to specify “no bgp enforce-first-as” (IOS, IOS-XE) as the route server does not insert its own ASN into the AS_path of relayed prefix announcements.

! Step 1 setup your IP filter for announcement to CNX 
ip prefix-list TO-CNX-RS4 seq 10 permit 10.1.0.0/16 le 24

! Step 2 add route-maps to control announcement
route-map bgp-cnx-rs4-out permit 10
 match ip address prefix-list TO-CNX-RS4

! Step 3 set higher local preference for CNX routes because IT'S FREE
! Step 4 DO NOT filter, because ? its free
route-map bgp-cnx-rs4-in permit 10
 set local-preference 300

! Step 5 setup BGP
router bgp your-asn

 bgp always-compare-med
 no bgp enforce-first-as
 bgp log-neighbor-changes

 neighbor CNX-RS4 peer-group 
 neighbor CNX-RS4 remote-as 132213  
 neighbor CNX-RS4 version 4
 neighbor CNX-RS4 transport connection-mode active

 neighbor 103.7.144.1 peer-group CNX-RS4
 neighbor 103.7.144.2 peer-group CNX-RS4
!
 address-family ipv4
  network 10.1.0.0/16
  neighbor CNX-RS4 next-hop-self
  neighbor CNX-RS4 route-map bgp-cnx-rs4-in in
  neighbor CNX-RS4 route-map bgp-cnx-rs4-out out  ! step 3
  neighbor 103.7.144.1 activate
  neighbor 103.7.144.2 activate
  exit-address-family

IPv4 peering Huawei

Example Huawei configuration for peering with CNX Route Server, replace 10.1.0.0/16 with your prefix delegation.

ip ip-prefix TO-CNX-RS4 index 10 permit 10.1.0.0 16 greater-equal 16 less-equal 24


route-policy bgp-cnx-rs4-out permit node 10
  if-match ip-prefix TO-CNX-RS4

route-policy bgp-cnx-rs4-in permit node 10
   apply local-preference 300

bgp your-asn
 undo check-first-as

 group CNX-RS4 external
 peer CNX-RS4 as-number 132213
 peer CNX-RS4 description CNX free domestic peering

 peer 103.7.144.1 group CNX-RS4
 peer 103.7.144.2 group CNX-RS4

 ipv4-family unicast
  network 10.1.0.0 255.255.0.0
  peer CNX-RS4 preferred-value 100
  peer CNX-RS4 route-policy bgp-cnx-rs4-out export
  peer CNX-RS4 route-policy bgp-cnx-rs4-in import
  peer CNX-RS4 next-hop-local
  peer CNX-RS4 enabled
  peer 103.7.144.1 enabled
  peer 103.7.144.1 enabled

please note the configuration has not been tested by CNX because we do not have a Huawei test router, it is build based on internet examples and feedback from peers.

IPv6 peering Cisco

Example Cisco configuration for peering with CNX Route Server, replace 2001:DB8:10::/48 with your prefix delegation.

router bgp your-asn

 bgp always-compare-med
 no bgp enforce-first-as
 bgp log-neighbor-changes

 neighbor CNX-RS6 peer-group 
 neighbor CNX-RS6 remote-as 132213  
 neighbor CNX-RS6 version 4
 neighbor CNX-RS6 transport connection-mode active

 neighbor 2001:DE8:1D::1 peer-group CNX-RS6
 neighbor 2001:DE8:1D::2 peer-group CNX-RS6
!
 address-family ipv6
 network 2001:DB8:10::/48
 neighbor CNX-RS6 next-hop-self
 neighbor CNX-RS6 route-map bgp-cnx-rs6-in in
 neighbor CNX-RS6 route-map bgp-cnx-rs6-out out
 neighbor 2001:DE8:1D::1 activate
 neighbor 2001:DE8:1D::2 activate
 exit-address-family

!
ipv6 prefix-list TO-CNX-RS6 seq 10 permit 2001:DB8:10::/48

!
route-map bgp-cnx-rs6-out permit 10
 match ipv6 address prefix-list TO-CNX-RS6

! set higher local preference for CNX routes
route-map bgp-cnx-rs6-in permit 10
 set local-preference 300