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New Member

Too many runts and CRC errors on 2924


i have one fa port of a cat2924XL connected to another fa port of a cat2950. Both ports are configured for 100Mbps/full and 802.1Q trunking. They are connected via 2 patton vdsl modems (2 wire line) that are 802.1Q compatible(the manual says so!!).

2950 at one end shows no input or output errors.

2924 at the other end has many input errors, crc, frame and mainly many runts!!

Every 20 seconds or so i get LINK-4 error interface fa 0/8 is experiencing errors at the console

When i disabled dot1Q and put both ports not in trunk but in access mode, there were none runts errors but only very few crc (1 crc error per 2 seconds for 4Mbps traffic.

The LINK-4 error message, existed but more rare.

I tried 10Mb/half or 10Mb/full but the sane things were happening.

Any ideas?

  • LAN Switching and Routing

Re: Too many runts and CRC errors on 2924

The modems must have some kind of ethernet settings on it I would check the setup info for the modems and try changing that end . If not able to be changed it may only accept autonegotiate which is maybe what you should try on both ends . If it only accepts auto then hardcoding the switchport will cause problems .

New Member

Re: Too many runts and CRC errors on 2924

the problem is that these patton modems have nothing to configure!!

the console port, according to the manual, should only be used by patton personel only.


Re: Too many runts and CRC errors on 2924

If there is nothing to configure then leave both switchports set as auto for speed and duplex and don't hardcode .


Re: Too many runts and CRC errors on 2924

If you read the specs for the unit it says the ports are autosensing so you have to leave the switchports as auto for speed and duplex .

New Member

Re: Too many runts and CRC errors on 2924

Hi Glen and many thanks for the interest.

The auto negotiation works fine between any port of cat2950 and the Patton.


between the cat2924XL and the patton nothing happens if i leave it to auto. That is why i had to configure the settings manually.

I have just managed to find another cat2950 and i am planning in replacing the old cat2924XL and what will happen.



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