135
NOTE:
If you execute the
display mpls te tunnel-interface
command immediately after an FRR, you can
see two CRLSPs in up state. This is because FRR uses the
make-before-break
mechanism to set
up a new LSP, and the old LSP is deleted after the new one has been established for a while.
# Verify that the bypass tunnel is in use on Switch B.
[SwitchB] display mpls lsp
FEC Proto In/Out Label Interface/Out NHLFE
1.1.1.1/4/61400 RSVP 1136/3 Tun5
2.2.2.2/5/30914 RSVP -/1149 Vlan4
3.2.1.2 Local -/- Vlan4
# On the PLR, configure the interval for selecting an optimal bypass tunnel as 5 seconds.
[SwitchB] mpls te
[SwitchB-te] fast-reroute timer 5
[SwitchB-te] quit
# On the PLR, bring up the protected interface VLAN-interface 2.
[SwitchB] interface vlan-interface 2
[SwitchB-Vlan-interface2] undo shutdown
# Execute the
display interface tunnel
4 command on Switch A to display information about the
primary CRLSP. The output shows that the tunnel interface is in up state. (Details not shown.)
# Wait for about 5 seconds, execute the
display mpls lsp verbose
command on Switch B. The
output shows that Tunnel 5 is bound to interface VLAN-interface 2 but not in use. (Details not
shown.)
# Execute the
display ip routing-table
command on Switch A. The output shows a static route entry
with interface Tunnel 4 as the output interface. (Details not shown.)
203B
Auto FRR configuration example
421B
Network requirements
Use RSVP-TE to set up a primary CRLSP that explicitly uses path Switch A—Switch B—Switch
C—Switch D.
Configure auto FRR on Switch B to automatically set up bypass tunnels for the primary CRLSP.
Configure BFD for RSVP-TE between Switch B and Switch C. When the link between Switch B and
Switch C fails, BFD can detect the failure quickly and notify RSVP-TE of the failure, so RSVP-TE can
switch traffic to the bypass tunnel.