228--------------------------------------------------------------------------14.14.14.0/24 10 NULL vlan200 DirectD/L/-44.44.44.44/32 10 NULL Loop0 DirectD/-/-12.12.12.0/32 10 NULL vlan200 14.14.14.4R/L/-22.22.22.22/32 10 NULL vlan200 14.14.14.4R/L/-Flags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/DownBit SetISIS(1) IPv4 Level-2 Forwarding Table-------------------------------------IPV4 Destination IntCost ExtCost ExitInterface NextHopFlags--------------------------------------------------------------------------14.14.14.0/24 10 NULL vlan200 DirectD/L/-44.44.44.44/32 10 NULL Loop0 DirectD/-/-12.12.12.0/32 10 NULL22.22.22.22/32 10 NULLFlags: D-Direct, R-Added to RM, L-Advertised in LSPs, U-Up/DownBit SetFrom the previous output information, you will see that the neighbor relationships and routinginformation on Switch A and Switch B have not changed. That is, the neighbors cannot sense theswitchover on Switch S.IS-IS FRR configuration exampleNetwork requirementsSwitch S, Switch A, and Switch D belong to the same IS-IS routing domain. They areinterconnected through IS-IS, as illustrated in Figure 71. When Link A between Switch S andSwitch D fails, traffic must be switched to Link B immediately.Figure 71 Network diagram for IS-IS FRR configurationSwitch S Switch DSwitch ALoop 01.1.1.1/32Vlan-int10012.12.12.1/24Vlan-int20013.13.13.1/24Vlan-int20013.13.13.2/24Vlan-int10012.12.12.2/24Vlan-int10124.24.24.2/24Vlan-int10124.24.24.4/24Loop 04.4.4.4/32Link ALink B
