We are upgrading a customer network and have found that users of a particular application [which is very bursty/bandwidth hungry] have experienced a marked performance drop. I see lots of output drops on the interfaces. This is only happening on 2960S-48 the rest of the users on 2960PSTL [all PoE] are not having nearly as bad a time. I have tried various QoS configs with little success. I have seen on some other blogs that the 2960S has less buffers than the rest of the family. An idea of this is true? Removing QoS or upping the users to 1Gb cures the performance problem. TIA ... View more

Hi I have 2 4900M connected together via a port-channel using 2 tengbe interfaces. The swtiches are right next to each other. The fiber patch leads are new. I am getting the following errors on both swithes [16 interfaces tried]: *May  4 10:57:13.191: %SFF8472-5-THRESHOLD_VIOLATION: Te1/1: Rx power low warning; Operating value: -13.7 dBm, Threshold value:  -9.9 dBm. *May  4 10:57:15.191: %SFF8472-5-THRESHOLD_VIOLATION: Te1/3: Rx power low alarm; Operating value: -14.6 dBm, Threshold value: -13.9 dBm.$HRESHOLD_VIOLATION: Te1/1: Rx power low warning; The port-channel then unbundles and sometimes the offending interface re-joins. I have placed another interface [te 1/8] into the port channel and this seems to stay up sh ver and sh transiever outputs below sh interfaces tenGigabitEthernet 1/1 transceiver detail ITU Channel not available (Wavelength not available), Transceiver is internally calibrated. mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable. ++ : high alarm, +  : high warning, -  : low warning, -- : low alarm. A2D readouts (if they differ), are reported in parentheses. The threshold values are calibrated.                               High Alarm  High Warn  Low Warn   Low Alarm           Temperature         Threshold   Threshold  Threshold  Threshold Port       (Celsius)          (Celsius)   (Celsius)  (Celsius)  (Celsius) --------- ------------------  ----------  ---------  ---------  --------- Te1/1       28.1                74.0        70.0         0.0       -4.0                               High Alarm  High Warn  Low Warn   Low Alarm            Voltage            Threshold   Threshold  Threshold  Threshold Port       (Volts)            (Volts)     (Volts)    (Volts)    (Volts) ---------  ---------------    ----------  ---------  ---------  --------- Te1/1      3.25                   N/A         N/A         N/A        N/A            Optical            High Alarm  High Warn  Low Warn   Low Alarm            Transmit Power     Threshold   Threshold  Threshold  Threshold Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm) ---------  -----------------  ----------  ---------  ---------  --------- Te1/1       -2.4                 2.9        -1.0        -7.3      -11.3            Optical            High Alarm  High Warn  Low Warn   Low Alarm            Receive Power      Threshold   Threshold  Threshold  Threshold Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm) -------    -----------------  ----------  ---------  ---------  --------- Te1/1      -13.6                 2.9        -1.0        -9.9      -13.9 sh ver Cisco IOS Software, Catalyst 4500 L3 Switch Software (cat4500e-IPBASEK9-M), Version 12.2(54)SG1, RELEASE SOFTWARE (fc1) Image text-base: 0x10000000, data-base: 0x12C41C68 ROM: 12.2(44r)SG5 Sushi Revision 11, Tatooine Revision 141, Forerunner Revision 1.78 uptime is 30 minutes System returned to ROM by power-on System image file is "bootflash:cat4500e-ipbasek9-mz.122-54.SG1.bin" WS-C4900M (MPC8548) processor (revision 2) with 524288K bytes of memory. Processor board ID JAE14360LUF MPC8548 CPU at 1.33GHz, Cisco Catalyst 4900M Last reset from PowerUp 20 Virtual Ethernet interfaces 20 Gigabit Ethernet interfaces 8 Ten Gigabit Ethernet interfaces 511K bytes of non-volatile configuration memory. Configuration register is 0x2101 I have seen issues like this before [and Q posted on forums] with the 3750 .. ANy ideas Thanks in advance ... View more