[c-nsp] Deny default route (From customer - BGP)

[Mark Tinka]

On 10/Mar/15 04:40, CiscoNSP List wrote:
> Hi Everyone,
>
> Only had a few hours sleep, so I may be overlooking something extremely obvious...but we are receiving a default from a customer, even though route-map/prefix list *should* block it...
> router bgp xxx
> ...
> address-family ipv4
> ...
> neighbor CUST_A route-map CUST_A-BGP-IN in
>
> ip prefix-list PL_DENY_DEFAULT seq 5 permit 0.0.0.0/0
> ip prefix-list PL_CUST_A_BGP_PREFIXES seq 5 permit xxx.xxx.xxx.0/24
>
> route-map CUST_A-BGP-IN deny 5
> match ip address prefix-list PL_DENY_DEFAULT
> route-map CUST_A-BGP-IN permit 10
>   match ip address prefix-list PL_CUST_A_BGP_PREFIXES
>   set community xxxxx:1400
>
> Weird thing is, that "sh ip bgp summary" shows that neighbour as only having 1 in "State/PfxRcd"
>
> but "sh ip bgp nei xxx.xxx.xx.xx received-routes" shows the neighbour with 0.0.0.0 and there single /24

Keep it simple - just use only the "PL_CUST_A_BGP_PREFIXES" prefixes, 
with its implicit "deny-all" at the end of it.

Apply on your "CUST_A-BGP-IN" sequence 10 route-map and you should be 
good. Whatever is not included in the prefix list will be dropped.

Mark.