Vpn Tunnel Features Supported By The S9300 - Huawei Quidway S9300 Configuration Manual

Quidway S9300 Terabit Routing Switch
Configuration Guide - VPN
If no tunnel policy is configured, the default tunnel policy is used. By default, an LSP is used
and load balancing is not performed among tunnels. That is, only one LSP can be selected.

1.2 VPN Tunnel Features Supported by the S9300

This section describes the VPN tunnel features supported by the S9300.
An application, such as VPN, chooses tunnels according to the tunnel policy. If the tunnel policy
is not created, the tunnel management module searches for a tunnel according to the default
policy.
The tunnel policy has the following modes:
l
l
These two modes are mutually exclusive.
Select-Sequence Mode
By using the tunnel policy in select-sequence mode, you can specify the sequence in which the
tunnels are used and the number of tunnels performing load balancing.
In a tunnel policy, tunnels are selected in sequence. If the tunnel with the highest priority is Up
and not bound with other sevices, it is selected regardless of whether other services have selected
it. The tunnels with lower priorities are not selected except in cases of load balancing or when
the tunnel with the highest priority is in Down state. For example, in a tunnel policy, both LSPs
and CR-LSPs can be selected and LSPs are prior to CR-LSPs. If LSPs do not exist, a VPN
chooses CR-LSPs. After an LSP is set up, the VPN selects the LSP and does not use the CR-
LSP anymore.
If multiple tunnels of the same type meet the requirements, the tunnel policy randomly chooses
one or more tunnels.
In select-sequence mode, if both CR-LSPs and LSPs are available, if CR-LSPs are prior to LSPs,
and if three tunnels are available for load balancing, then the rule for choosing a tunnel is as
follows:
l
l
l
l
l
Issue 01 (2009-07-28)
Select-sequence
Tunnel binding
The CR-LSPs in Up state are preferred. If the number of CR-LSPs that are Up is smaller
than 3 (CR-LSPs are not sufficient or CR-LSPs are sufficient but their status is Down), the
CR-LSPs are preferred and the LSPs in Up state are also selected.
Three tunnels are selected and one of the tunnels is an LSP. If a CR-LSP is added or a CR-
LSP in Down state becomes Up, the CR-LSP is selected and the LSP is not used anymore.
If the number of tunnels for load balancing is smaller than a specified value and a CR-LSP
or an LSP in Up state is added, the new tunnel participates in load balancing.
The number of tunnels for load balancing depends on the number of tunnels that meet the
requirements. For example, if only one CR-LSP and one LSP are in Up state, load balancing
is performed between the CR-LSP and the LSP. The tunnels of other types are not selected
even if they are Up.
Load balancing among tunnels differs from load balancing among routes. For example,
when load balancing is performed among three CR-LSPs, the CR-LSPs may be on the same
path; when load balancing is performed among three routes, the routes are on different
paths.
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