Huawei quidway s7700 Configuration Manual page 466

Quidway S7700 Smart Routing Switch
Configuration Guide - VPN
The Kompella supports both local and remote connections. It supports inter-AS L2VPN in the
following two modes:
l
l
The Kompella VLL adopts the label block to allocate the labels. Through the label blocks, labels
can be allocated to connections at the same time.
Users specify the local CE range that indicates the number of CEs that can be connected with
this CE. The PE assigns a label block for this CE. The size of the label block is equal to the CE
range. In this manner, the users can reserve some extra labels for the VPN for future use. On a
short term basis, it is a waste of label resources, but it reduces the workload of VPN deployment
and configuration in expansion.
Suppose an enterprise VPN has 10 CEs and the number may increase to 20 due to its service
expansion in future. The CE range of each CE can be set to 20 to meet future expansion. If the
VPN adds nodes in the future, it is necessary to modify the configuration of the PE that is directly
connected with the new CE, without modifying other PEs.
Inter-AS VLL
The realization of an inter-AS VLL depends on the actual environment. In CCC mode, the label
is of single layer. Therefore, the inter-AS can be realized after the static LSP is set up between
the ASBRs.
SVC, Martini and Kompella modes can realize the inter-AS Option A (VRF-to-VRF) . In the
L2VPN networking, the link type between the ASBRs and that of the VC must be the same. In
the inter-AS Option A, each ASBR must reserve a sub-interface for each inter-AS VC. If the
number of the inter-AS VCs is small, the Option A can be adopted. Compared with the L3VPN,
the inter-AS Option A of the L2VPN consume more resources,so it is not recommended.
Option C is a better solution. The SP network devices need only set up the outer tunnel on the
PEs of different ASs. The ASBR need not maintain information about the inter-AS L2VPN. The
ASBR also need not reserve interfaces for the inter-AS L2VPN. L2VPN information is
exchanged only between PesPEs only. The exchange requires a low consumption of resources,
and the configuration workload does not increase.
The S7700 does not support Option C.
Access Mode
When configuring a VLL, you need to configure the interface (that is, AC interface) connecting
the PE to the CE.
On the S7700, a VLL supports the following interfaces to be configured as AC interfaces:
l
l
l
l
l
l
l
Issue 01 (2011-07-15)
Multi-hop mode: adopts routes with BGP label.
MP-EBGP mode: saves label block on the ASBR.
XGE interfaces
XGE sub-interfaces
GE interfaces
GE sub-interfaces
Ethernet interfaces
Ethernet sub-interfaces
Eth-Trunk interfaces
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
5 VLL Configuration
451