IS-IS NSR configuration example
Network requirements
As shown in Figure 48, Switch S, Switch A, and Switch B belong to the same IS-IS routing domain.
Run IS-IS on all the switches to interconnect them with each other.
Enable IS-IS NSR on Switch S to ensure forwarding continuity between Switch A and Switch B when an active/standby switchover occurs on Switch S.
Figure 48: Network diagram
Configuration procedure
Configure the IP addresses and subnet masks for interfaces on the switches. (Details not shown.)
Configure IS-IS on the switches to make sure Switch S, Switch A, and Switch B can communicate with each other at Layer 3 and dynamic route update can be implemented among them with IS-IS. (Details not shown.)
Enable IS-IS NSR on Switch S.
<SwitchS> system-view [SwitchS] isis 1 [SwitchS-isis-1] non-stop-routing [SwitchS-isis-1] return
Verifying the configuration
# Reoptimize process placement on Switch S to trigger an active/standby switchover.
<SwitchS> system-view [SwitchS] placement reoptimize Predicted changes to the placement Program Current location New location --------------------------------------------------------------------- syslog 0/0 0/0 diagusageratio 0/0 0/0 l3vpn 0/0 0/0 fc 0/0 0/0 dns 0/0 0/0 lauth 0/0 0/0 aaa 0/0 0/0 lsm 0/0 0/0 rm 0/0 0/0 rm6 0/0 0/0 track 0/0 0/0 ip6addr 0/0 0/0 ipaddr 0/0 0/0 rpm 0/0 0/0 trange 0/0 0/0 tunnel 0/0 0/0 lagg 0/0 0/0 bfd 0/0 0/0 acl 0/0 0/0 slsp 0/0 0/0 usr6 0/0 0/0 usr 0/0 0/0 qos 0/0 0/0 fczone 0/0 0/0 ethbase 0/0 0/0 ipcim 0/0 0/0 ip6base 0/0 0/0 ipbase 0/0 0/0 eth 0/0 0/0 eviisis 0/0 0/0 ifnet NA NA isis 0/0 1/0 Continue? [y/n]:y Re-optimization of the placement start. You will be notified on completion Re-optimization of the placement complete. Use 'display placement' to view the new placement
# During the switchover period, display IS-IS neighbor information on Switch A to verify the neighborship between Switch A and Switch S.
<SwitchA> display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0001
Interface: vlan100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 25s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0001
Interface: vlan100 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 27s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Switch A to verify that Switch A has a route to the loopback interface of Switch B.
<SwitchA> display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL vlan100 Direct D/L/-
22.22.22.22/32 10 NULL Loop0 Direct D/-/-
14.14.14.0/32 10 NULL vlan100 12.12.12.2 R/L/-
44.44.44.44/32 10 NULL vlan100 12.12.12.2 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
12.12.12.0/24 10 NULL vlan100 Direct D/L/-
22.22.22.22/32 10 NULL Loop0 Direct D/-/-
14.14.14.0/32 10 NULL
44.44.44.44/32 10 NULL
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
# Display IS-IS neighbor information on Switch B to verify the neighborship between Switch B and Switch S.
<SwitchB> display isis peer
Peer information for IS-IS(1)
----------------------------
System Id: 0000.0000.0001
Interface: vlan200 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 25s Type: L1(L1L2) PRI: 64
System Id: 0000.0000.0001
Interface: vlan200 Circuit Id: 0000.0000.0001.01
State: Up HoldTime: 27s Type: L2(L1L2) PRI: 64
# Display IS-IS routing information on Switch B to verify that Switch B has a route to the loopback interface of Switch A.
<SwitchB> display isis route
Route information for IS-IS(1)
-----------------------------
Level-1 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
14.14.14.0/24 10 NULL vlan200 Direct D/L/-
44.44.44.44/32 10 NULL Loop0 Direct D/-/-
12.12.12.0/32 10 NULL vlan200 14.14.14.4 R/L/-
22.22.22.22/32 10 NULL vlan200 14.14.14.4 R/L/-
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
Level-2 IPv4 Forwarding Table
-----------------------------
IPv4 Destination IntCost ExtCost ExitInterface NextHop Flags
-------------------------------------------------------------------------------
14.14.14.0/24 10 NULL vlan200 Direct D/L/-
44.44.44.44/32 10 NULL Loop0 Direct D/-/-
12.12.12.0/32 10 NULL
22.22.22.22/32 10 NULL
Flags: D-Direct, R-Added to Rib, L-Advertised in LSPs, U-Up/Down Bit Set
The output shows that the neighbor information and routing information on Switch A and Switch B have not changed during the active/standby switchover on Switch S. The neighbors are unaware of the switchover.