211
{
Configure a routing protocol, and enable MPLS and LDP on the interface connected to an
internal router of the AS.
{
Specify the PE in the same AS as an IBGP peer, and the ASBR in a different AS as an
EBGP peer.
{
Enable BGP to exchange labeled IPv4 unicast routes with the PE in the same AS and the
ASBR in different AS.
{
Enable MPLS capability on the interface connected to the ASBR in another AS. There is no
need to configure a label distribution protocol, for example, LDP.
{
(Optional.) Configure a routing policy to determine which IPv4 unicast routes are advertised
to the IBGP or EBGP peer with MPLS labels.
In addition, configure BGP to advertise routes destined for a PE on PEs or ASBRs. For more
information, see
Layer 3—IP Routing Configuration Guide
.
472B
Configuring a PE
To configure a PE for inter-AS option C:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP instance view.
bgp
as-number
[
instance
instance-name
]
[
multi-session-thread
]
N/A
3.
Configure the ASBR in the
same AS as an IBGP peer.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
as-number
as-number
By default, no BGP peers exist.
4.
Configure the PE of another
AS as an EBGP peer.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
as-number
as-number
By default, no BGP peers exist.
5.
Create the BGP IPv4 unicast
address family and enter its
view.
address-family ipv4
[
unicast
]
By default, the BGP IPv4 unicast
address family is not created.
6.
Enable BGP to exchange
IPv4 unicast routes with the
ASBR in the same AS.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
enable
By default, BGP does not
exchange IPv4 unicast routes with
any peer.
7.
Enable BGP to exchange
labeled IPv4 routes with the
ASBR in the same AS.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
label-route-capability
By default, BGP cannot exchange
labeled routes with any IPv4 peer
or peer group.
8.
Return to BGP instance view.
quit
N/A
9.
Enter BGP VPNv4 address
family view.
address-family vpnv4
N/A
10.
Enable BGP to exchange
VPNv4 routes with the PE in
different ASs.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
enable
By default, BGP cannot exchange
VPNv4 routes with any peer.
11.
(Optional.) Configure the PE
to not change the next hop of
routes advertised to the peer.
peer
{
group-name
|
ipv4-address
[
mask-length
] }
next-hop-invariable
Configure this command on the
RR so the RR does not change
the next hop of advertised VPNv4
routes.
473B
Configuring an ASBR
To set up an inter-AS public tunnel for the inter-AS option C solution, an ASBR must assign an MPLS
label to the route destined for a PE, and advertise the label along with the route. Typically, the routes
advertised by an ASBR through BGP include the PE address as well as other routes. You can
