11-04-2007 09:23 PM
Hello
Is it possible to configure the 3750 switch to send a snmp trap whenever there is a crc error on its ports?
Thank you
11-05-2007 07:11 AM
No specific trap for CRC errors, but you can use RMON to create a threshold and trap:
Here is a sample on how to configure your router to send an snmp trap when ifInErrors are over a threshold.
First, you need to know what interface you care and find out the ifIndex. On NetView box:
snmpwalk -c your_read_community_string the_router_ip_address ifDescr
You should see something like:
interfaces.ifTable.ifEntry.ifDescr.1 : DISPLAY STRING- (ascii): ATM1/0/0
interfaces.ifTable.ifEntry.ifDescr.2 : DISPLAY STRING- (ascii): Fddi1/1/0
interfaces.ifTable.ifEntry.ifDescr.3 : DISPLAY STRING- (ascii): ATM4/0
interfaces.ifTable.ifEntry.ifDescr.4 : DISPLAY STRING- (ascii): Serial5/0/0
interfaces.ifTable.ifEntry.ifDescr.5 : DISPLAY STRING- (ascii): Serial5/0/1
interfaces.ifTable.ifEntry.ifDescr.6 : DISPLAY STRING- (ascii): Serial5/0/2
interfaces.ifTable.ifEntry.ifDescr.7 : DISPLAY STRING- (ascii): Serial5/0/3
interfaces.ifTable.ifEntry.ifDescr.8 : DISPLAY STRING- (ascii): Ethernet5/1/0
interfaces.ifTable.ifEntry.ifDescr.9 : DISPLAY STRING- (ascii): Ethernet5/1/1
If I am interested in Serial5/0/1, then the index is 5.
conf t
rmon event 3 log trap public description "Too many errors" owner cisco
rmon event 4 log trap public description "Errors are now below threshold" owner cisco
rmon alarm 2 ifEntry.14.5 60 delta rising-threshold 200 3 falling-threshold 100 4 owner
cisco
The above says, if index 5 of ifInErrors (which is ifEntry.14.5) is above 200 over 60
seconds, then send event 3 trap, once it goes below 100 each 60 second, send event 4 trap.
You can this with other traps. You might also want to look at the object locIfInCRC specifically for CRC errors.
11-10-2007 03:52 PM
Thank you for the reply.
Is it possible to configure this for all interface? Reason is I have a 4 switch (48 ports each) stackwise configuration. It would be too much to configure that one for each interface.
Thanks again.
11-11-2007 09:41 PM
HI, [PLS RATE if HELPS]
Depending on your IOS version, you may be able to do this with the Embedded Event Manager.
Here is a sample EEM applet that will poll for input CRC errors every 60 seconds on interface FastEthernet0/0, and log them using syslog:
event manager applet crc_check
event interface name FastEthernet0/0 parameter input_errors_crc poll-interval 60 entry-op ge entry-val-is-increment true entry-val 1
action 1.0 syslog msg "CRC found on interface $_interface_name : $_interface_value"
Refer the Attachments (.pdf) for More Details on EEM.
PLS RATE if HELPS
Best Regards,
Guru Prasad R
11-13-2007 08:03 PM
seems that I can't monitor multiple ports at any one time.
11-13-2007 08:15 PM
HI,
Please Rate if HELPS
You can study the EEM Document and can write multiple such Applet to Monitor the Traffic.
Refer the Sample Applet Posted in my earlier POST.
"Do RATE ALL HELPFUL POSTS"
Best Regards,
Guru Prasad R
11-13-2007 10:33 PM
Solved this by incrementing the event id for each interface interested.
11-13-2007 10:32 PM
davistan
Thank you for the response.
I have sent up rmon on the interfaces that I am interested. However, I understand I need to configure SNMP too?
Any ideas?
11-14-2007 02:57 PM
Yes, you will also need to configure snmp so that the traps can be sent.
A very basic snmp config would look like:
snmp-server community public RO
snmp-server enable traps
snmp-server host 1.1.1.1 public traps
Of course you should substitute public with a more secure community string and replace 1.1.1.1 with a valid host IP address.
11-18-2007 10:35 PM
i am interested in knowing the difference between traps sent by snmp, and by using RMON.
Daviston,
I have an STM-1 link on my core router, but the traps that i have did not report me the link updown information when there was a downtime due to fiber cut .. Here are the traps that i have cnfigured already.
snmp-server engineID local ENGINEID
snmp-server community STRING RO
snmp-server community STRING_W RW
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps chassis
snmp-server enable traps module
snmp-server enable traps transceiver all
snmp-server enable traps ds1
snmp-server enable traps eigrp
snmp-server enable traps casa
snmp-server enable traps tty
snmp-server enable traps ospf state-change
snmp-server enable traps ospf errors
snmp-server enable traps ospf retransmit
snmp-server enable traps ospf lsa
snmp-server enable traps ospf cisco-specific state-change nssa-trans-change
snmp-server enable traps ospf cisco-specific state-change shamlink interface-old
snmp-server enable traps ospf cisco-specific state-change shamlink neighbor
snmp-server enable traps ospf cisco-specific errors
snmp-server enable traps ospf cisco-specific retransmit
snmp-server enable traps ospf cisco-specific lsa
snmp-server enable traps atm subif
snmp-server enable traps bgp
snmp-server enable traps bulkstat collection transfer
snmp-server enable traps config-copy
snmp-server enable traps config
snmp-server enable traps event-manager
snmp-server enable traps frame-relay
snmp-server enable traps frame-relay subif
snmp-server enable traps hsrp
snmp-server enable traps ipmulticast
snmp-server enable traps MAC-Notification move threshold
snmp-server enable traps msdp
snmp-server enable traps pim neighbor-change rp-mapping-change invalid-pim-message
snmp-server enable traps rf
snmp-server enable traps rtr
snmp-server enable traps slb real virtual csrp
snmp-server enable traps bridge newroot topologychange
snmp-server enable traps stpx inconsistency root-inconsistency loop-inconsistency
snmp-server enable traps syslog
snmp-server enable traps mvpn
snmp-server enable traps mpls traffic-eng
snmp-server enable traps mpls fast-reroute protected
snmp-server enable traps mpls ldp
snmp-server enable traps mpls rfc ldp
snmp-server enable traps pw vc
snmp-server enable traps isakmp policy add
snmp-server enable traps isakmp policy delete
snmp-server enable traps isakmp tunnel start
snmp-server enable traps isakmp tunnel stop
snmp-server enable traps ipsec cryptomap add
snmp-server enable traps ipsec cryptomap delete
snmp-server enable traps ipsec cryptomap attach
snmp-server enable traps ipsec cryptomap detach
snmp-server enable traps ipsec tunnel start
snmp-server enable traps ipsec tunnel stop
snmp-server enable traps ipsec too-many-sas
snmp-server enable traps flash insertion removal
snmp-server enable traps memory bufferpeak
snmp-server enable traps flex-links status
snmp-server enable traps csg agent quota-server database
snmp-server enable traps sonet
snmp-server enable traps fru-ctrl
snmp-server enable traps entity
snmp-server enable traps resource-policy
snmp-server enable traps ethernet cfm cc mep-up mep-down cross-connect loop config
snmp-server enable traps ethernet cfm crosscheck mep-missing mep-unknown service-up
snmp-server enable traps cpu threshold
snmp-server enable traps rsvp
snmp-server enable traps srp
snmp-server enable traps vtp
snmp-server enable traps vlancreate
snmp-server enable traps vlandelete
snmp-server enable traps c6kxbar intbus-crcexcd intbus-crcrcvrd swbus
snmp-server enable traps dot1x
snmp-server enable traps envmon fan shutdown supply temperature status
snmp-server enable traps port-security
snmp-server enable traps alarms minor
snmp-server enable traps vlan-mac-limit
snmp-server enable traps mpls vpn
snmp-server host HOST_NAME KEY
11-19-2007 03:56 AM
a snmp trap is a predefined information in the MIB for a specific state change of the value of a certain MIB object or the SNMP agent itself and thus automatically implemented on a device if the SNMP agent on the device supports this MIB. It is not possible to change the information in this predefined trap - it is just possible to enable or disable it.
Whereas with RMON you have the possibility to monitor the value of (any) MIB object of your choice (like CRC counter) and define
1) the intervall at which to look at the value of the MIB object
2) the way how to look at the value (dalta or absolute)
3) define the critical value (rising-/falling threshold value)
this makes a 'rmon alarm'
and send a trap with your own description if your conditions are getting hit - which is the 'rmon event'
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/ffun_c/fcfprt3/fcf016.htm
If you don't get a trap when your link goes down then either
- there is 'no snmp trap links-status' configured at the interface level- or it is a sub interface on a physical interface where the physical inter does not goes down when the subinterface goes down (protocol down)
in this situation you can use the rmon feature as davistan wrote or as it is described here
11-21-2007 11:35 PM
OK i am good to configure RMON.. But i have a question...
It says, promiscuous mode (RMON monitors all packets on LAN segment) is more intensive than the native mode (RMON monitors onlu the packets normally received by the interface).
is there anyway i could in advanced, be aware of risks associated with configuring RMON in native mode, just for 5 interfaces? Whould i have to test it by hit and trial?
11-22-2007 12:24 AM
if you search on Cisco.com for "rmon commands" (with quotes) you will get a good list with documentation on this. But I do not know of a document that describes how to calculate the effect when configuring rmon and I think this is not possible because it depends on the hardware, CPU, RAM and overall traffic and other config options (e.g. encryption) that interfere with the overall performance of a device.
HTH
-if it does, please rate or mark your questions as resolved if you open a thread, so other members of the forum see that a thread has valuable information
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