53
Strict explicit path
—Among the nodes that the path must traverse, a node and its previous
hop must be connected directly.
Loose explicit path
—Among the nodes that the path must traverse, a node and its
previous hop can be connected indirectly.
Strict explicit path precisely specifies the path that an MPLS TE tunnel must traverse. Loose
explicit path vaguely specifies the path that an MPLS TE tunnel must traverse. Strict explicit
path and loose explicit path can be used together to specify that some nodes are directly
connected and some nodes have other nodes in between.
Setting up a CRLSP through RSVP-TE
After calculating a path by using CSPF, MPLS TE uses a label distribution protocol to set up the
CRLSP and reserves resources on each node of the path.
The device supports the label distribution protocol of RSVP-TE for MPLS TE. Resource Reservation
Protocol (RSVP) reserves resources on each node along a path. Extended RSVP can support MPLS
label distribution and allow resource reservation information to be transmitted with label bindings.
This extended RSVP is called RSVP-TE.
For more information about RSVP, see "
."
Traffic forwarding
After an MPLS TE tunnel is established, traffic is not forwarded on the tunnel automatically. You must
direct the traffic to the tunnel by using one of the following methods.
Static routing
You can direct traffic to an MPLS TE tunnel by creating a static route that reaches the destination
through the tunnel interface. This is the easiest way to implement MPLS TE tunnel forwarding. When
the traffic to multiple networks is to be forwarded through the MPLS TE tunnel, you must configure
multiple static routes, which are complicated to configure and difficult to maintain.
For more information about static routing, see
Layer 3—IP Routing Configuration Guide
.
Automatic route advertisement
You can also configure automatic route advertisement to forward traffic through an MPLS TE tunnel.
Automatic route advertisement distributes the MPLS TE tunnel to the IGP (OSPF or IS-IS), so the
MPLS TE tunnel can participate in IGP routing calculation. Automatic route advertisement is easy to
configure and maintain.
Automatic route advertisement can be implemented by using the following methods:
•
IGP shortcut
—Also known as AutoRoute Announce. It considers the MPLS TE tunnel as a link
that directly connects the tunnel ingress node and the egress node. Only the ingress node uses
the MPLS TE tunnel during IGP route calculation.
•
Forwarding adjacency
—Considers the MPLS TE tunnel as a link that directly connects the
tunnel ingress node and the egress node and advertises the link to the network through an IGP,
so every node in the network uses the MPLS TE tunnel during IGP route calculation.
Содержание FlexNetwork 5510 HI Series
Страница 9: ...vii Remote support 460 Documentation feedback 460 Index 462 ...
Страница 318: ...309 Request list 0 Retransmit list 0 ...
Страница 363: ...354 Verify that CE 1 and CE 2 can ping each other Details not shown ...
Страница 446: ...437 The MCE has redistributed the OSPF routes of the two VPN instances into the EBGP routing tables of PE 1 ...