Displaying and Maintaining IS-IS Configuration 905The Graceful Restart interval on a router is used as the holdtime in the IS-IS HelloPDUs so that its neighbors can maintain the adjacencies within the interval afterthe router restarts.By setting the SA (Suppress-Advertisement) bit in the hello PDUs sent by the GRRestarter, its neighbors will not advertise adjacencies within the specified perioduntil the completion of LSDB synchronization between the GR Restarter and itsneighbors. This feature helps to effectively avoid blackhole routes due to thesending or receiving of LSPs across the restart.n A device can act as both a GR Restarter and GR Helper at the same time.Follow these steps to configure GR on the GR Restarter and GR Helperrespectively:Displaying andMaintaining IS-ISConfigurationTo do... Use the command... RemarksEnter system view system-view -Enable IS-IS, and enter IS-ISviewisis [ process-id ][ vpn-instancevpn-instance-name ]RequiredDisabled by defaultEnable the GR capability forIS-ISgraceful-restart RequiredDisabled by defaultSet the Graceful Restartintervalgraceful-restart intervaltimerRequired300 seconds by defaultConfigure to set the SA bitduring restartgraceful-restartsuppress-saOptionalBy default, the SA bit is notset.To do... Use the command... RemarksDisplay brief IS-IS information display isis brief [ process-id |vpn-instance vpn-instance-name ]Available in any viewDisplay the status of thedebug switchdisplay isis debug-switches{ process-id | vpn-instancevpn-instance-name }Available in any viewDisplay information aboutIS-IS enabled interfacesdisplay isis interface [ [ traffic-eng |verbose ] * | tunnel ] [ process-id |vpn-instance vpn-instance-name ]Available in any viewDisplay IS-IS licenseinformationdisplay isis license Available in any viewDisplay IS-IS LSDB information display isis lsdb [ [ l1 | l2 | level-1 |level-2 ] | [ lsp-id LSPID | lsp-namelspname ] | local | verbose ] *[ process-id | vpn-instancevpn-instance-name ]Available in any viewDisplay IS-IS mesh groupinformationdisplay isis mesh-group [ process-id| vpn-instance vpn-instance-name ]Available in any viewDisplay thehost-name-to-system-IDmapping tabledisplay isis name-table [ process-id |vpn-instance vpn-instance-name ]Available in any view
