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device is a 6500 series router
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What could have caused this?<br />
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<br />
Today we added a monitor port on one of our routers.<br />
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This is a standard procedure that we have performed in the past on several other devices.<br />
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A physical interface (uplink port) was set as the source and the remote vlan was set as the destination. <br />
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The remote vlan was only trunked across a single link to another router.<br />
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The other router was setup with a monitor source of the remote vlan and destination of the physical uplink to the sniffer.<br />
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Both of the routers in question are part of an HSRP pair.<br />
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Both of the routers in question are running FWSM.<br />
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When the monitor port was enabled, the cpu usage spiked to 100% causing HSRP flapping.<br />
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The remote router was no longer responding to pings due to cpu usage.<br />
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What could have caused this?


Today we added a monitor port on one of our routers.

This is a standard procedure that we have performed in the past on several other devices.

A physical interface (uplink port) was set as the source and the remote vlan was set as the destination. 

The remote vlan was only trunked across a single link to another router.

The other router was setup with a monitor source of the remote vlan and destination of the physical uplink to the sniffer.

Both of the routers in question are part of an HSRP pair.

Both of the routers in question are running FWSM.

When the monitor port was enabled, the cpu usage spiked to 100% causing HSRP flapping.

The remote router was no longer responding to pings due to cpu usage.



Cisco router CPU spike after adding monitor session to remote-span vlan

A router is a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. The most familiar type of routers are home and small office cable or DSL routers that simply pass data, such as web pages, email, IM, and videos between computers and the Internet. More sophisticated routers, such as enterprise routers, connect large business or ISP networks up to the powerful core routers that forward data at high speed along the optical fiber lines of the Internet backbone. Though routers are typically dedicated hardware devices, use of software-based routers has grown increasingly common.

Routers

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switches / Hubs

Networking is the process of connecting computing devices, peripherals and terminals together through a system that uses wiring, cabling or radio waves that enable their users to communicate, share information and interact over distances. Often associated are issues regarding operating systems, hardware and equipment, cloud and virtual networking, protocols, architecture, storage and management.