Cisco process list

Reference:The show processes Command

The Processes

The table below explains the individual processes in the show processes, show processes cpu, and show processes memory outputs. This is not an exhaustive list.

Process	Explanation
ARP Input	Handles incoming Address Resolution Protocol (ARP) requests
BGP I/O	Handles reading, writing, and executing Border Gateway Protocol (BGP) messages
BGP Scanner	Scans the BGP and main routing tables to ensure consistency (this is a separate process since it can be quite time-consuming)
BGP Router	Main BGP process which starts when the configuration is fully loaded
BOOTP Server	The gateway's Bootstrap Protocol (BOOTP) server process
CallMIB Background	Deletes the call history if the call history ages out and gathers call information
CDP Protocol	Main Cisco Discovery Protocol (CDP) - handles the initialization of CDP for each interface If incoming packet, monitors the CDP queue and timers, then processes it If timer event, sends update
Check heaps	Checks the memory every minute. It forces a reload if it finds processor corruption.
Compute load avgs	Computes the five minute, exponentially-decayed output bit rate of each network interface, and the loading factor of the entire system. The load average is computed using the following formula: average = ((average - interval) * exp (-t/C)) + interval where t = 5 seconds and C = 5 minutes, exp (-5/60*5)) = .983 Computes the load of each interface (one by one), and checks the back-up interface's load (enables them or shuts them down according to the load).
*Dead*	Processes as a group that is now dead. See Troubleshooting Memory Problems for more details.
Exec	Handles console exec sessions; has a high priority
Hybridge Input	Handles incoming transparent bridge packets that slip through the fast paths
*Init*	System initialization
IP Background	Called upon when you change the encapsulation (for example, when an interface moves to a new state, an IP address changes, when you add a new Data Exchange Interface (DXI) map, or when some dialer timers expire) Does the periodic aging of the Internet Control Message Protocol (ICMP) redirect cache Modifies the routing table according to the status of the interfaces
IP Cache Ager	Ages the routing cache and heals stale recursive routes. The ager runs once every time interval (once a minute by default) and checks to make sure that a recursive routing change has not made the entry invalid. Another function of this ager is to make sure that the entire cache gets refreshed approximately every 20 minutes.
IP Input	Process-switched IP packets
IP-RT Background	Periodically revises the gateway of last resort and IP static routes. This process is called on demand, right after the static routes (which the gateway of last resort may depend on) have been revised.
ISDNMIB Background	Sends ISDN trap service and deletes the call queue if it ages out
ISDN Timers	Handles ISDN carrier timer events
Load Meter	Computes the load average for the different processes every five seconds, and the five minute exponentially-decayed busy time. The load average is computed using the following formula: average = ((average - interval) * exp (-t/C)) + interval, where: t = 5 seconds and C = 5 minutes, exp (-5/(60*5)) = .983~= 1007/1024 t = 5 seconds and C = 1 minute, exp (-5/60)) = .920~= 942/1024
Multilink PPP out	Processes multilink packets that have been queued from fast-switching (outbound half fast-switching)
Net Background	Performs a variety of network-related background tasks. These tasks must be performed quickly and may not block for any reason. The tasks that are called in the net_background process (for example, interface dethrottling) are time critical. Executes the "Compute load avgs", "Per-minute Jobs", and "Net Input" processes Handles interface throttling
Net Input	Handles otherwise unknown packets. This is done at process level so that input queuing comes into play. If you operate at interrupt level, you could very easily lock up the router. Handles some known protocols which you may decide should be offered to bridging. In this case, net_input either sends the packet to NULL, or bridges it.
Net Periodic	Performs interface periodic functions every second such as: resetting the periodic counter clearing the input error rate counter checking serial lines for restarting from glitches performing any periodic keep-alive functions checking protocol routing table consistency doing bridge state consistency checking announcing line protocol up or down events
Per-minute Jobs	Performs the following tasks once a minute: analyzes stack usage announces low stacks executes registered one_minute jobs
Per-second Jobs	Performs a variety of tasks every second; executes registered one_second jobs
Pool Manager	Manager process for managing growth and discarding requests from dynamic pools at the interrupt level
PPP Manager	Manages all PPP Finite State Machine (FSM) operations by processing PPP input packets and interface transitions Monitors the PPP queue and the PPP timers (negotiation, authentication, idle, and others) Note: By serializing events that might be detected which interrupt routines in other processes, many common bugs can be avoided.
OSPF Router	Main Open Shortest Path First (OSPF) process
OSPF Hello	The OSPF process which receives hello
*Sched*	The Scheduler
Serial Background	Watches events and branches to the correct service routine for each expired event (mainly reset of interfaces)
Spanning Tree	Executes the Spanning Tree Protocol (STP), a single process that handles the multiple spanning tree algorithm Monitors the STP Queue: Process incoming STP packets Monitors the STP timers: Hello timer Topology change timers Digital Equipment Corporation (DEC) short age out timer Forward delay timer Message age timer
Tbridge Monitor	Dispatches "interesting packets" to the appropriate handler ("interesting traffic" is Cisco Group Management Protocol (CGMP), Internet Group Management Protocol (IGMP), OSPF packets [multicasts] Monitors multicast timers which check station entry age-outs and circuit group active circuits
TCP Driver	Handles the sending of packet data over a Transmission Control Protocol (TCP) connection. It includes opening or closing connections, or dropping packets when queues are full. Remote Source-Route Bridging (RSRB), serial tunneling (STUN), X.25 switching, X.25 over TCP/IP (XOT), Data-link Switching (DLSW), translation, and all TCP connections starting or ending at the router currently use TCP Driver.
TCP Timer	Handles retransmission of timeout packets
Virtual exec	Handles virtual type terminal (vty) lines (for example, Telnet sessions on the router).