Setting the Overload BitAnother use for the overload bit is to prevent other routers from using this router as an intermediate hopin their shortest path first (SPF) calculations. For example, if the IS-IS routing database is out of memoryand cannot accept new LSPs, Dell Networking OS sets the overload bit and IS-IS traffic continues totransit the system.To set or remove the overload bit manually, use the following commands.• Set the overload bit in LSPs.ROUTER ISIS modeset-overload-bitThis setting prevents other routers from using it as an intermediate hop in their shortest path first (SPF)calculations.• Remove the overload bit.ROUTER ISIS modeno set-overload-bitExample of Viewing the Overload Bit SettingWhen the bit is set, a 1 is placed in the OL column in the show isis database command output. Theoverload bit is set in both the Level-1 and Level-2 database because the IS type for the router isLevel-1-2.Dell#show isis databaseIS-IS Level-1 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OLB233.00-00 0x00000003 0x07BF 1074 0/0/0eljefe.00-00 * 0x0000000A 0xF963 1196 0/0/1eljefe.01-00 * 0x00000001 0x68DF 1108 0/0/0eljefe.02-00 * 0x00000001 0x2E7F 1099 0/0/0Force10.00-00 0x00000002 0xD1A7 1088 0/0/0IS-IS Level-2 Link State DatabaseLSPID LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OLB233.00-00 0x00000006 0xC38A 1110 0/0/0eljefe.00-00 * 0x0000000E 0x53BF 1196 0/0/1eljefe.01-00 * 0x00000001 0x68DF 1108 0/0/0eljefe.02-00 * 0x00000001 0x2E7F 1099 0/0/0Force10.00-00 0x00000004 0xCDA9 1093 0/0/0Dell#Debugging IS-ISTo debug IS-IS processes, use the following commands.• View all IS-IS information.EXEC Privilege modedebug isis• View information on all adjacency-related activity (for example, hello packets that are sent andreceived).EXEC Privilege modedebug isis adj-packets [interface]418 Intermediate System to Intermediate System
