When the GRE tunnel is used as part of a provisioned SDP, the following command is relaxed to allow the user to configure a source address for an GRE SDP:
config>service>sdp>local-end ip-address
The default value of the local-end parameter is the primary IPv4 address of the system interface. To change the local-end address, the SDP must be shut down.
The primary IPv4 address of any local network IP interface, loopback or otherwise, may be used as the source address. The address does not need to match the primary address of an interface which has the MPLS-over-GRE termination subnet configured, unless a GRE SDP or tunnel from the far-end router terminates on this address.
The address of the following interfaces are not supported:
unnumbered network IP interface
IES interface
VPRN interface
CSC VPRN interface
The following rules apply to the local-end command:
A maximum of 15 distinct address values can be configured for all GRE SDPs under the config>service>sdp>local-end context, and all L2oGRE SDPs under the config>service>system>gre-eth-bridged>tunnel-termination context.
The same source address cannot be used in both contexts because an address configured for a L2oGRE SDP matches an internally created interface which is not available to other applications.
The local-end address of a GRE SDP, when different from system, need not match the primary address of an interface which has the MPLS-over-GRE termination subnet configured, unless a GRE SDP or tunnel from the far-end router terminates on this address.
The user must ensure that the local-end address is reachable from the far-end router that terminates the GRE SDP. To help ensure reachability, the interface for this address may be added to IGP or BGP, or a static route may be configured on the far-end router.
The following services can be bound to a GRE SDP when the local-end address is modified:
VPRN or IES with a spoke-sdp interface
(config>service>vprn>interface>spoke-sdp)
VPLS with provisioned a spoke SDP
BGP-AD VPLS and use-provisioned-sdp or prefer-provisioned-sdp option enabled
BGP-VPLS and use-provisioned-sdp or prefer-provisioned-sdp or prefer-provisioned option enabled
Epipe with provisioned a spoke SDP
Epipe with BGP-VPWS and use-provisioned-sdp or prefer-provisioned-sdp or prefer-provisioned option enabled
For services that support auto-binding to a GRE tunnel, a new CLI command is introduced to configure a single alternate source address per system:
config>service>system>vpn-gre-source-ip ip-address
The default value is the primary IPv4 address of the system interface.
A change to the value of the vpn-gre-source-ip parameter can be performed without shutting down the service. After the new value is configured, the system address is not used in services that bind to the GRE tunnel.
The primary IPv4 address of any local network IP interface, loopback or otherwise, may be used.
The address of the following interfaces are not supported:
unnumbered network IP interface
IES interface
VPRN interface
CSC VPRN interface
The following rules apply to the vpn-gre-source-ip parameter value:
This single source address counts toward the maximum of 15 distinct address values per system that are used by all GRE SDPs under the config>service>sdp>local-end context and all L2oGRE SDPs under the config>service>system>gre-eth-bridged>tunnel-termination context.
The same source address can be used in both vpn-gre-source-ip and config>service>sdp>local-end contexts.
The same source address cannot be used in both vpn-gre-source-ip and config>service>system>gre-eth-bridged>tunnel-termination contexts because an address configured for a L2oGRE SDP matches an internally created interface that is not available to other applications.
The vpn-gre-source-ip address, when different from system, need not match the primary address of an interface which has the MPLS-over-GRE termination subnet configured, unless a GRE SDP or tunnel from the far-end router terminates on this address.
The following contexts can use a GRE tunnel when the source IP address is modified:
VPRN service with a SDP (config>service>vprn>spoke-sdp)
VPRN auto-bind-tunnel
The source address cannot be configured for the following services with auto-created GRE-SDP:
BGP-AD VPLS
BGP-VPLS
VGP-VPWS
An alternative solution to bind any one of these services to its own specific GRE SDP with its own source IP address, is to tag a pre-provisioned GRE SDP with a SDP admin-group (sdp-group command) and include the admin-group with the PW template binding of this service (config>service>pw-template policy-id [use-provisioned-sdp]> sdp-include group-name). The command prefer-provisioned-sdp can also be used.