F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices Network Management Configuration Guide-6PW100

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Only routes passing all the configured policies can be received.
To configure BGP route reception filtering policies:
Ste
p
Command Remarks
515. Enter system view.
system-view
N/A
516. Enter BGP view or
BGP-VPN instance
view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance vpn-instance-name
Use either approach.
517. Configure BGP route
reception filtering
policies.
• Reference an ACL or IP prefix list to filter incoming
routes from all peers :
filter-policy { acl-number | ip-prefix ip-prefix-name }
import
• Reference a routing policy to filter routing information
from a peer or peer group:
peer { group-name | ip-address } route-policy
route-policy-name import
• Reference an ACL to filter routing information from a
peer or peer group:
peer { group-name | ip-address } filter-policy
acl-number import
• Reference an AS path list to filter routing information
from a peer or peer group:
peer { group-name | ip-address } as-path-acl
as-path-acl-number import
• Reference an IP prefix list to filter routing information
from a peer or peer group:
peer { group-name | ip-address } ip-prefix
ip-prefix-name import
Use at least one
approach.
By default, no route
reception filtering is
configured.
1494BEnabling BGP and IGP route synchronization
Enable BGP and IGP route synchronization in an AS to avoid giving wrong directions to routers.
By default, upon receiving an IBGP route, a BGP router checks the route's next hop. If the next hop is
reachable, the BGP router advertises the route to EBGP peers. If a non-BGP router works in an AS, it can
discard a packet due to an unreachable destination. As shown in
2693HFigure 292, Router E has learned a
route of 8.0.0.0/8 from Router D through BGP. Router E then sends a packet to 8.0.0.0/8 through Router
D, which finds from its routing table that Router B is the next hop (configured using the peer
next-hop-local command). Because Router D has learned the route to Router B through IGP, Router D
forwards the packet to Router C through route recursion. Router C does not know the route 8.0.0.0/8, so
it discards the packet.