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How to look for errors on my routers
I have recently installed two Cisco 2811 and one 2801 router in my network. What is the best way to watch the interfaces to look for errors or loops. we are having an intermittant latency and packet dropping issues. I want to check for mismatches and stuff like that
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show controllers <i>serial interface</i>
the best way is to use the show interface command like photg mentioned, but you can also use the show logging command if you have logging enabled on the router.
CRC errors usually mean that you have speed/duplex mismatch or that you have a bad cable.
also, the show interface command will show you if there are a large amount of broadcast packets sent to each port. you can use the clear counters command to reset on the info.
CRC errors usually mean that you have speed/duplex mismatch or that you have a bad cable.
also, the show interface command will show you if there are a large amount of broadcast packets sent to each port. you can use the clear counters command to reset on the info.
you could also use some sort of snmp logger like PRTG to collect info on a port and identify issues as they happen... from http://www.paessler.com/prtg
PRTG Traffic Grapher is an easy to use Windows software for monitoring bandwidth usage as well as various other network parameters like memory and CPU utilization. It provides system administrators with live readings and periodical usage trends of leased lines, routers, firewalls, servers, and many other network devices. The most common usage is bandwidth usage monitoring, but you can also monitor many other aspects of your network.
All common methods for network usage data acquisition are supported:
* SNMP: Simple Network Management Protocol is the basic method of gathering bandwidth and network usage data. It can be used to monitor bandwidth usage of routers and switches port-by-port as well as device readings like memory, CPU load etc.
* Packet Sniffing: With its Packet Sniffer PRTG can inspect all network data packets passing a network card. You can monitor either only the traffic of the machine running PRTG or all network traffic by using a switch with a "monitoring" port.
* Netflow: The Netflow protocol is supported by most Cisco routers to measure bandwidth usage. Although being the most complex type to set up it is also the most powerful method suitable for high traffic networks.
* Note: With packet sniffer and netflow based monitoring you can measure the traffic by IP address and/or protocol while SNMP based measurement is port based only.
PRTG Traffic Grapher is an easy to use Windows software for monitoring bandwidth usage as well as various other network parameters like memory and CPU utilization. It provides system administrators with live readings and periodical usage trends of leased lines, routers, firewalls, servers, and many other network devices. The most common usage is bandwidth usage monitoring, but you can also monitor many other aspects of your network.
All common methods for network usage data acquisition are supported:
* SNMP: Simple Network Management Protocol is the basic method of gathering bandwidth and network usage data. It can be used to monitor bandwidth usage of routers and switches port-by-port as well as device readings like memory, CPU load etc.
* Packet Sniffing: With its Packet Sniffer PRTG can inspect all network data packets passing a network card. You can monitor either only the traffic of the machine running PRTG or all network traffic by using a switch with a "monitoring" port.
* Netflow: The Netflow protocol is supported by most Cisco routers to measure bandwidth usage. Although being the most complex type to set up it is also the most powerful method suitable for high traffic networks.
* Note: With packet sniffer and netflow based monitoring you can measure the traffic by IP address and/or protocol while SNMP based measurement is port based only.