3com S7906E Instruccion De Instalación

 

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If you start OSPF but do not configure the router ID, the system will automatically elect one. 

However, the same election rules produce the same router ID. Therefore, you are recommended to 

configure the router ID when starting an OSPF process. For the election rules, refer to OSPF 

Configuration in the IP Routing Volume.  

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If you configure multiple OSPF VPN instances but do not configure the route tag, the system will 

automatically create one based on the AS number configured. If you do not configure BGP, the tag 

will be 0. However, the same calculation rule produces the same tag, and hence the same tag will 

be created for multiple OSPF VPN instances on the same PE or PEs with the same AS number. 

Therefore, you are recommended to configure different tags for different OSPF VPN instance. 

 

Before configuring BGP AS number substitution, complete these tasks: 

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Configuring basic MPLS L3VPN 

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Configuring CEs at different sites to have the same AS number 

When CEs at different sites have the same AS number, you need to configure the BGP AS number 

substitution function to avoid route loss. 

With the BGP AS number substitution function, when a PE advertises a route to a CE of the specified 

peer, if an AS number identical to that of the CE exist in the AS_PATH of the route, it will be replaced 

with that of the PE before the route is advertised. 

Follow these steps to configure the BGP AS number substitution function: 

Enter system view 

— 

Enter BGP view 

bgp as-number 

Required 

Enter BGP VPN instance view 

ipv4-family vpn-instance 
vpn-instance-name 

Required 

Enable the BGP AS number 
substitution function 

peer { ip-address | 
group-name } substitute-as 

Required 

Disabled by default 

 

For information about the peer { ip-address | group-name } substitute-as  command, refer to BGP 

Commands in the IP Routing Volume.