Brocade Multi-Service IronWare Administration Guide (Supporting R05.6.00) - Manual (Page 231)

Multi-Service IronWare Administration Guide 213
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LSP ping and traceroute
6
One-to-one Fast ReRoute (FRR) LSPs
Similar to the redundant LSPs, a ping or traceroute on a one-to-one FRR LSP is performed on the
active path. If a path switchover occurs while a ping or traceroute is in-progress, the echo request
continues to be sent out on the old active path. This implies that the echo request sent after path
switchover will time out.
A user can ping or trace the route of the ingress-originated detour of a one-to-one FRR LSP by
specifying the detour parameter. The operation is started only if the detour is operationally up.
FRR bypass LSPs
The LSP ping and traceroute facilities support FRR bypass LSPs. You can ping or trace the
protected LSP and bypass tunnel separately.
You can ping or trace the ingress-originated or transit-originated bypass tunnel by specifying either
the name of bypass LSP (as you would any regular LSP name) or the entire RSVP session ID
(including the tunnel endpoint, the tunnel ID, and the extended tunnel ID).
NOTE
In the current facility backup implementation, the bypass LSP name must be unique in the system
(for example, the name cannot be the same as the regular LSP name).
The traceroute output of a backup tunnel depends on the setting of the propagate-ttl and
label-propagate-ttl options. If both propagate-ttl and label-propagate-ttl options are turned on, the
traceroute output shows the detail of the bypass path. If both options are turned off, the bypass
path is shown as a single hop. The options should be either both ON or both OFF.
To trace the route of a backup path, the TTL of the bypass and protected labels (if they are not
implicit NULL labels) are set as in the following example:
• Both propagate-ttl and label-propagate-ttl are ON: TTL = 1, 2, 3, and so on, are set for both
labels.
• Otherwise: bypass label TTL is set to 255. Protected label TTL is set to 1, 2, 3, and so on.
IP TTL is set to topmost label TTL. Otherwise, it is set to 255.
Transit-originated detour
The user can initiate a ping or traceroute operation on a transit-originated, detour LSP. Because the
session name does not uniquely identify a session on a transit LSR, the user needs to specify the
entire session ID (including the tunnel endpoint, tunnel ID, and extended tunnel ID) for the detour
LSP to which the LSP ping or traceroute command is applied.
LSP reoptimization
If LSP reoptimization happens while the ping or traceroute is operating, the echo request is still
sent out on the current LSP instance until the new instance is created. This avoids displaying
partial information from the old and new paths if they are different; particularly for a traceroute.
Similarly, if the ping or traceroute operation is started while LSP reoptimization is occurring, the
LSP label, out interface, and other parameters from the currently up instance will be used.