User manual JUNIPER NETWORKS JUNOSE 11.2.X BGP AND MPLS CONFIGURATION

[. . . ] JunosETM Software for E SeriesTM Broadband Services Routers BGP and MPLS Configuration Guide Release 11. 2. x Published: 2010-07-16 Copyright © 2010, Juniper Networks, Inc. Juniper Networks, Inc. 1194 North Mathilda Avenue Sunnyvale, California 94089 USA 408-745-2000 www. juniper. net Juniper Networks, Junos, Steel-Belted Radius, NetScreen, and ScreenOS are registered trademarks of Juniper Networks, Inc. The Juniper Networks Logo, the Junos logo, and JunosE are trademarks of Juniper Networks, Inc. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners. [. . . ] The acknowledging peer also determines whether the requesting peer is reflecting back the acknowledging peer's source instance. It compares the destination instance value in each request message with the source instance value that it most recently advertised to the requesting peer. If the requesting peer advertises a wrong value in the destination instance field of the request message, then the acknowledging peer treats the requesting peer as if communication has been lost. 262 Copyright © 2010, Juniper Networks, Inc. Chapter 3: MPLS Overview Behavior of Both Peers When no hello messages are received from a peer within the configured hello interval, the peer is treated as if communication has been lost. When a peer determines that communication has been lost, it can reinitiate the sending of hello messages. In this case, the peer generates a new source instance different than the one it previously used for communication with its peer. Related Topics · Configuring RSVP-TE Hello Messages to Determine Peer Reachability on page 297 RSVP-TE Graceful Restart Overview RSVP-TE graceful restart enables routers to maintain MPLS forwarding state when a link or node failure occurs. In a link failure, control communication is lost between two nodes, but the nodes do not lose their control or forwarding state. A node failure occurs when the LSR has a failure in the RSVP-TE control plane, but not in the data plane. Traffic can continue to be forwarded while RSVP-TE restarts and recovers. The graceful restart feature supports the restoration and resynchronization of RSVP-TE states and MPLS forwarding state between the restarting router and its RSVP-TE peers during the graceful restart recovery period. The RSVP-TE graceful restart feature enables an LSR to gracefully restart, to act as a graceful restart helper node for a neighboring router that is restarting, or both. Announcement of the Graceful Restart Capability LSRs use the RSVP-TE hello mechanism to announce their graceful restart capabilities to their peer RSVP-TE routers. Both restarting LSRs and helper LSRs include the restart_cap object in hello requests and hello acks. The restart_cap object specifies both the graceful restart time and the graceful restart recovery time: · restart time--The sum of how long it takes the sender to restart RSVP-TE after a control plane failure plus how long it takes to reestablish hello communication with the neighboring RSVP-TE routers. recovery time--The period within which you want neighboring routers to resynchronize with the sending router's RSVP-TE state and MPLS forwarding state after the peers have re-established hello communication. The restarting LSR advertises the configured or default recovery time only while the graceful restart is in progress. When the LSR is not currently restarting or when it is incapable of preserving its MPLS forwarding state during the restart, the LSR advertises a recovery time of zero. · Both the restarting router and neighboring GR helper routers save the restart and recovery times that they receive from their peers. Restarting Behavior When the control plane fails, the LSR stops sending hello messages to its RSVP-TE neighbors. However, as a restarting router the LSR can continue to forward MPLS traffic Copyright © 2010, Juniper Networks, Inc. 263 JunosE 11. 2. x BGP and MPLS Configuration Guide because it preserves its MPLS forwarding state during the restart. When RSVP-TE comes back up, the restarted router sends the first hello message to its neighbors with a new source instance value to indicate that it had a control plane failure. The recovery time included in this hello message is set to zero only if the router was unable to preserve the MPLS forwarding state or to support control state recovery. When a neighboring router that has been configured as a graceful restart helper determines that the number of continuous missing hellos has reached the configured hello miss limit, it declares the router to be down. The helper router then waits for a period equal to the restart time that it received from the router and stored before the failure. During this period, the helper router preserves the restarting router's RSVP-TE state and MPLS forwarding state for the established LSPs and keeps forwarding MPLS traffic. [. . . ] Priority value for the VPWS instance for the multihomed site; displayed only when the value for the Multi-homed field is Yes Route targets configured for the VPWS instance Layer 2 interface that is a member of the VPWS instance Local customer site ID configured on the layer 2 interface Remote customer site ID configured on the layer 2 interface Administrative state of the connection, disabled or enabled Operational state of the connection, up or down Site-Priority Route Targets Interface Local-Site-Id Remote-Site-Id Admin state Oper state Related Topics · show l2vpn instance Monitoring L2VPN Interfaces for VPWS Purpose Display configuration and status information for interfaces on the router that are that are configured to be members of VPWS L2VPNs in the current VR. You can display information for a specific L2VPN interface, for all L2VPN interfaces in the specified VPWS instance, or for all L2VPN interfaces in all VPWS instances. The detail keyword displays detailed information about the specified L2VPN interface or all L2VPN interfaces. To display L2VPN interface information for a particular VPWS instance: host1#show l2vpn interface instance l2vpn1 MPLS shim interface ATM2/0. 100 ATM circuit type is AAL5 Member of L2VPN instance l2vpn1 Local site ID is 1 Remote site ID is 2 Control word is preferred by default Do send sequence numbers by default Relay format is atm-aal5-sdu-vcc by default Administrative state is enabled Operational state is up Operational MTU is 9180 Action Copyright © 2010, Juniper Networks, Inc. 675 JunosE 11. 2. x BGP and MPLS Configuration Guide MPLS shim interface UID is 0x2d000007 Lower interface UID is 0x0b000005 Condensed location is 0x00020000 Received: 3 packets 204 bytes 19 errors 0 discards Sent: 0 packets 0 bytes 0 errors 0 discards queue 0: traffic class best-effort, bound to atm-vc ATM2/0. 100 Queue length 0 bytes Forwarded packets 0, bytes 0 Dropped committed packets 0, bytes 0 Dropped conformed packets 0, bytes 0 Dropped exceeded packets 0, bytes 0 Meaning Table 141 on page 676 lists the show l2vpn interface command output fields. Table 141: show l2vpn interface Output Fields Field Name MPLS shim interface ATM circuit type Member of L2VPN instance Local site ID Remote site ID Control word send sequence numbers Relay format Field Description Type and specifier for MPLS shim interface Type of ATM circuit Name of the VPWS instance to which the interface belongs Local customer site ID configured on the interface Remote customer site ID configured on the interface Local preference for the control word, preferred or not preferred Local preference for sequence numbers, send or don't send Type of signaling and encapsulation used by the router for layer 2 traffic Administrative state of the interface, enabled or disabled Operational state of the interface, up or down Maximum allowable size in bytes of the maximum transmission unit for the interface UID automatically assigned to the MPLS shim interface when it is created UID automatically assigned to the MPLS major interface when it is created Administrative state Operational state Operational MTU MPLS shim interface UID Lower interface UID 676 Copyright © 2010, Juniper Networks, Inc. Chapter 16: Monitoring VPWS Table 141: show l2vpn interface Output Fields (continued) Field Name Condensed location Field Description Internal, platform-dependent, 32-bit representation of the interface location, used by Juniper Networks Customer support for troubleshooting. [. . . ]