Is-Is Features Supported By The Ne80E/40E - Huawei Quidway NetEngine80E Configuration Manual

HUAWEI NetEngine80E/40E Router
Configuration Guide - IP Routing
Figure 7-2
Level-1 and the Level-2 routers, and are used to establish the backbone network together with
the other Level-2 routers.The IS-IS backbone network does not refer to a specific area, in this
topology, no area is specified as a backbone area. All the Level-2 routers constitute an IS-IS
backbone network. The devices may belong to different areas, but the areas must be successive.
Figure 7-2 IS-IS topology II
L1
This type of networking shows differences between IS-IS and OSPF. For OSPF, the inter-area
routes are forwarded by the backbone area and the SPF algorithm is used in the same area. For
IS-IS, both Level-1 routers and Level-2 routers use the SPF algorithm to generate Shortest Path
Trees (SPTs).
Network Types
IS-IS supports only two network types, which can classify as follows according to physical links:
l
l

7.1.2 IS-IS Features Supported by the NE80E/40E

The NE80E/40E supports various Intermediate System-to-Intermediate System (IS-IS) protocol
features, including multi-instance, multi-process, hot standby (HSB), local multicast-topology
(MT), multi-topology, graceful restart (GR), traffic engineering (TE), administrative tags, Link
State Protocol Data Unit (LSP) fragment extension, dynamic host name exchange, route
summarization, load balancing, IS-IS Preference, fast convergence, Bidirectional Forwarding
Detection (BFD), and three-way handshake.
Multi-Instance and Multi-Process
IS-IS supports multi-process and multi-instance, facilitating management and improving control
efficiency of IS-IS.
Issue 02 (2014-09-30)
shows another type of IS-IS topology. The Level-1-2 routers are used to connect the
L1
Area2
L1/L2
Broadcast links such as Ethernet and Token-Ring.
Point-to-point links such as PPP and HDLC.
NOTE
For a Non-Broadcast Multi-Access (NBMA) network such as ATM, you need to configure sub-interfaces
for it. The type of subnets cannot be Point-to-Multipoint (P2MP). IS-IS cannot run on P2MP networks.
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Area1
L2
L1/L2
L2
Area3
L2
7 IS-IS Configuration
L1
Area4
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