Issues blackholing an IP using BGP with community strings

[Brandon Baker]

I am trying to blackhole an ip with an upstream provider but am having no luck. They say they are not receiving the community string from me. This is what I am entering:

6461:5990 is Zayo blackhole community

conf t

route-map ddos permit 10

set community 6461:5990

ip route X.X.128.88 255.255.255.255 Null0

router bgp (AS NUMBER)

neighbor (zayo ip) send-community

network X.X.128.88 mask 255.255.255.255 route-map ddos

I have also just tried

ip route X.X.128.88 255.255.255.255 Null0

ip access-list permit 24 X.X.128.88

route-map ddos permit 10

match ip address 24

set community 6461:5990

router bgp (AS NUMBER)

neighbor (zayo ip) route-map ddos out

neighbor (zayo ip) send-community

Does anyone see anything wrong with either of these commands?

[paul driver]

Hello

can you post the output from this please:

sh ip bgp neighbors | s Neighbor capabilities


res
Paul

[Brandon Baker]

It may be working now- I am awaiting a response from Zayo:

here is the requested output:

Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised and received
    Address family IPv4 Unicast: advertised and received
    Graceful Restart Capability: received
      Remote Restart timer is 120 seconds
      Address families advertised by peer:
        IPv4 Unicast (was not preserved
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised and received
    Address family IPv4 Unicast: advertised and received
    Graceful Restart Capability: received
      Remote Restart timer is 120 seconds
      Address families advertised by peer:
        none
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised and received
    Address family IPv4 Unicast: advertised and received
    Graceful Restart Capability: received
      Remote Restart timer is 120 seconds
      Address families advertised by peer:
        none
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised
    Address family IPv4 Unicast: advertised and received
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised
    Address family IPv4 Unicast: advertised and received
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised
    Address family IPv4 Unicast: advertised and received
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised
    Address family IPv4 Unicast: advertised and received
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1
  Neighbor capabilities:
    Route refresh: advertised and received(new)
    Four-octets ASN Capability: advertised
    Address family IPv4 Unicast: advertised and received
    Enhanced Refresh Capability: advertised
    Multisession Capability:
    Stateful switchover support enabled: NO for session 1

[paul driver]

Hello

This is what I was looking for on you bgp peerings   <---  Four-octets ASN Capability: advertised and received

Which mean both sides ogf the peering support that feature however I did notice just the advertised on one of them

res
Paul

[CSCO12744192]

Hello Brandon Baker,

it may be silly question but want to insure , did you have insure also that network is being seeing at the advertisement list to the peer by :

show ip bgp neighbors (zayo ip) advertise

also i don't know if you have entered it but in order to use the community from the syntax XXXX:XXXX and not XXXXXXXX you should enter:

ip bgp-community new-format , that because by default the bgp display this community as 4byte number but when it command entered it display it as 2byte/2byte community that may be the problem.