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Re: FCS recieve errors and giant rx error

 
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Occasional Advisor

FCS recieve errors and giant rx error

i have a problem with hp 2920 switch, in which it is showing lot of fcs recieve errors and giant rx errors. This switch is connected to core switch (5400 series switch) through fiber. From this forum i followed troubleshooting by replacing trancievers , cables etc. But again its showing these errors. The error is showing only on port 45(uplink/tagged port->connection to core sw). My question is that will a pc connected to 2920 switch cause this problem. I cannot come to conclusion tht pc is a culprit because when i checked other ports for FCS recieve errors ,theres nothing its coming only from tagged port(trunk port->cisco term). Please help me to resolve this problem.

7 REPLIES 7
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Respected Contributor

Re: FCS recieve errors and giant rx error

A few things to check:

* are you using the same model transceiver at both ends (MM/SM)? Original HP transceivers?

* what is the length of the fiber connection? Check if the length is within spec of the type of cable you are using (OM1-OM4 for multimode).

* are jumbo frames enabled for any of the vlans on the trunk?

* what speed are you using for the link, 1G or 10G? Are both ports set to Auto speed/duplex?

* did the errors start recently? Did you do any network changes just before the errors started?

 

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Occasional Advisor

Re: FCS recieve errors and giant rx error

yes same model transceivers  at both ends (LX1000 j4859c)

single mode connection, distance is less than 1km

Jumbo frames not enabled for the vlans.

speed of link is 1G, both end is in auto mode

errors started recently, no changes was made to the network.

 

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Honored Contributor

Re: FCS recieve errors and giant rx error

As per your screenshot, (probably Dual Personality) Port 48 (why you wrote Port 45 then?) on Aruba 2920 (right?) shows that Port Statistics report a total of 11 FCS Read Errors since switch boot or since last (statistic) clear...so...a question: at some point after you saw that FCS Read Errors value, did you cleared port's statistic counters to better diagnose if those errors are still present (current) and are eventually growing?

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Occasional Advisor

Re: FCS recieve errors and giant rx error

Its port 48(by mistake i specified as 45), yes its eventually growing ,now its showing 145 fcs rx error.

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Honored Contributor

Re: FCS recieve errors and giant rx error

Wait...if no Duplex mismatch is present...then are those transceivers working with Single-Mode or Multi-Mode fiber optic?

  • 2 m - 550 m (multi-mode fiber with 62,5 µm/125 µm core/cladding diameter, 500 MHz * km bandwidth)
  • 2 m - 550 m (multi-mode fiber with 50 µm/125 µm core/cladding diameter, 400 MHz * km bandwidth)
  • 2 m - 550 m (multi-mode fiber with 50 µm/125 µm core/cladding diameter, 500 MHz * km bandwidth)
  • 2 m - 10,000 m (single-mode fiber)

If you're working with Multi-Mode Fiber Optic cables then...550 meters are the maximum admitted for the cable run (so 1000 meters are too long).

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Occasional Advisor

Re: FCS recieve errors and giant rx error

single mode fiber are used.

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Occasional Advisor

Re: FCS recieve errors and giant rx error

As per the lastest screenshot 28.JPG