Cisco Switching/Routing :: 2960G High Output Drops Only On Gigabit Switch
Feb 11, 2013
I just got a Cisco 2960G 24-port gigabit switch so that our HP servers can have a Gigabit connection to the network. I moved 2 servers to it (HP Proliant DL380's) but they don't actually seem to be able to achieve even close to 1000Gbps. I ran same some LAN bandwidth tests and it was showing only around 200-300 Mbps between all of them. I also ran a network stress test utility, LAN Tornado, and it was showing packet loss as high as 60% when on gigabit, and only .07% when on 100Mbps.
-Both the NIC's and the switch ports are set to 1000/Full
-Currently using Cat5e cabling no more than 25Ft in length (I know Cat6 would be better but Cat5e is supposed to support Gigabit)
-All servers are on the same VLAN
Here are the port statistics when running just a stress test @ 10Mbps that had a 45% packet loss. What's odd though is when I set the servers and switches to 100Mbps, I get less than 1% packet loss.
GigabitEthernet1/0/16 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 203a.07ff.7e90 (bia 203a.07ff.7e90)
MTU 9000 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
Our database server is connected on cisco swich 2960G gigabitEthernet 0/38.while showing the interface command the total output drops is a large value..Is there any issue with this value.I think this is one of the reason for slow access of the server.
cisco6#show interfaces gigabitEthernet 0/38 GigabitEthernet0/38 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is 58bc.2746.45a6 (bia 58bc.2746.45a6)
I have quite a few 2960's in a manufacturing environment that are experiencing a large number of Total Output Drops. The gigabit uplinks arn't even close to fully subscribed and if I'm lucky they run at a peak of 4 - 5 Mb on a 1Gb uplink. Something really funky is going on. The individual switchports seem to have the total output drops and the uplinks at 1Gb do not have any output drops and never peak above 20Mb over a 3 month span on a 1Gb link.
We are seeing some high output drops on our 3560G's and I'm wondering if there is anything I can do to solve this, or should I just be looking at an upgrade.I do not have qos enabled:
do-rs-ah-3560g#show mls qos QoS is disabled QoS ip packet dscp rewrite is enabled
I don't have anything special configured apart from some trunk ports, otherwise its mostly defaults.Should I enable qos and tweak the buffering?
Have got 2 6500 in VSS. I'm seeing unsual high output drops. IOS Version: advipservicesk9-mz.151-1.SY.bin
Seeing too much output drops on interface ( in millions). When checked buffers ( output pasted below), it also shows enourmous drops.Not too sure, but is this normal or is there something fishy; which needs to be investigated. [code]
What is the cause of having a huge number ( 875349) of total output drops on one of my gigabit utp port gi 2/12 which is connected to Cisco 1841 fa0/0 router by mean of cat5e cable.I did change the cable from cat5e to cat 6 and tried to increase hold queue to 4096 and to tweak wrr queue bandwidth
One of my Catalyst 3750 switch have many out drops, I execute "sh mls qos int g2/0/3 statist" command, there are many output drops in queue3 threshold3. [code]
Am experiencing high output drops o int Gi 46,47,48 2950 int fa 22 23 and 24 are conneced to 3750 Gi 46,47,48 core sw1 3750 is connected to 2950 sw2 and vice versa
I have a 3560X that is directly connected to an ASA 5505. I am seeing output drops on the 3560X interface that connects to the ASA. Below are the troubleshooting commands I have ran, but I don't see any indication to what is causing the problem.
3560X show run int gig 0/24 ! interface GigabitEthernet0/24
I have too much output drops in my cisco 7206 VxR NPE G1 router. I'm doing dot1Q on this interface and is connected to switch , i changed the router and IOS but still the error is same . What can be the reason . The interface on switch and router are 1000/Full and i changed the cable also . The traffic only comes about max70Mbps and it is really confusing. [code]
I have 2 Cat-6506's that are used for my WiSM's. The only thing in both Chassis is 2 X WiSMs a SUP-7203A and a 6516A line card.The only connection between the rest of the network and these chassis is on port gig 1/2.[code] If I have read other posts correctly all points to the ASIC being overun by that traffic being sent from my WiSMs out to the Network.
I've got a recurring them developing across several deployments of Catalyst 3750X series switches, I'm seeing large amount of output drops across multiple ports but there are is no QoS deployed on any of these switches. (standard FiFO). As it happens the ports in question are a member of EtherChannel groups which are connected to ESX Hosts.I've also seen this behaviour also unexplained on another 3750X at a different site, however it's a single port and connects to an Upstream firewall.However in both cases neither switch has any QoS or non-standard configuration, literally a couple of VLAN's and some EtherChannel groups.Here's some output from the case involving the ESX servers.
I have seen an error in GRE configured between two routers over WAN. i am monitoring the WAN link and GRe tunnel via WhatsupGold NMS and it reported that Gre tunnel having packet loss sometimes and this time it affects the services and traffic passing over tunnel.sh int t101 shows output drops . is that the problem ? i have read that i have to adjust MTC size but i tried to change the tunnel MTU to 1400 but still sh int t101 shows MTU as 1514 ? What could be the problem of output drops in my tunnel link. [code]
I have a Catalyst Switch that is been used as a SAN switch providing ISCSI connection for servers.The total output drops of the interfaces connected to the SAN and some connected to the servers keep increasing.
Example below:
SWESAN1-1#sh interfaces gigabitEthernet 0/1 GigabitEthernet0/1 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is ec44.763c.8f01 (bia ec44.763c.8f01)MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 5/255Encapsulation ARPA, loopback not setKeepalive set (10 sec)Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTXinput flow-control is off, output flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00Last input never, output 00:00:08, output hang neverLast clearing of "show interface" counters 03:25:04Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 78Queueing strategy: fifoOutput queue: 0/40 (size/max)5 minute input rate 22322000 bits/sec, 2171 packets/sec5 minute output rate 5155000 bits/sec, 1487 packets/sec20441503 packets input, 23941254166 bytes, 0 no bufferReceived 0 broadcasts (0 multicasts)0 runts, 0 giants, 0 throttles0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored0 watchdog, 0 multicast, 0 pause input0 input packets with dribble condition detected16323602 packets output, 9608971046 bytes, 0 underruns0 output errors, 0 collisions, 0 interface resets0 babbles, 0 late collision, 0 deferred0 lost carrier, 0 no carrier, 0 PAUSE output0 output buffer failures, 0 output buffers swapped out
I have a problem with Total Output Drops, it's increase and decreases on WS-C3750E-48TD-E.
SWCIACTCT05#sh int gi1/0/47 | i Total output drops: Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 6487344 SWCIACTCT05#sh int gi1/0/47 | i Total output drops: Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 6487344 SWCIACTCT05#sh int gi1/0/47 | i Total output drops: Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 6487344
[code]....
I checked and found two registered bug id: CSCtq86186 / CSCso81660.I would like to know what is the best IOS version to update my switch, IOS 15.0.2 SE2 or 12.2.58 SE2, by the way, my environment is very critical (data center) and the version 15.0.2 SE2 is very recent, but its stable ?In both versions the problem are fixed?
i noticed the "output drops" increasing in interface gi 1/0/1 in my switch 2960-S although the utilization of my interface is between 20% and 50 %
SW__A#sh interfaces gigabitEthernet 1/0/1 GigabitEthernet1/0/1 is up, line protocol is up (connected) MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 93/255, rxload 3/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec)
I'm currently trying to diagnose a re-occuring problem with output drops on an uplink interface to a SonicWALL firewall, between 1am - 3am every night we receive alerts that the output drops (discards) counter has incremented.
This time frame happens to be when several network based backups are running so that's probably to blame for the added traffic count but I'm trying to narrow down what's actually dropping the traffic.
The switch hardware is a WS-C3750X-48 running C3750E-UNIVERSALK9-M , 12.2 (55) SE3.
My current thinking is that the output drops are indicative of congestion on the link to the SonicWALL indicating that the SonicWALL unit is incapable of processing the traffic flow fast enough thus causing the congestion and ultimately the output drops on the Gi2/0/48 interface.
According to SonicWALL the unit is rated at 1.5Gbps throughput without UTM services (pure stateful), and no UTM services are enabled.
I've posted a section of the show interface command:
Keepalive set (10 sec) Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX input flow-control is off, output flow-control is unsupported
I've got a recurring them developing across several deployments of Catalyst 3750X series switches, I'm seeing large amount of output drops accross multiple ports but there are is no QoS deployed on any of these switches. (standard FiFO).
As it happens the ports in question are a member of EtherChannel groups which are connected to ESX Hosts.I've also seen this behaviour also unexplained on another 3750X at a different site, however it's a single port and connects to an Upstream firewall.
However in both cases neither switch has any QoS or non-standard configuration, literally a couple of VLAN's and some EtherChannel groups.Here's some output from the case involving the ESX servers:
Port-channel6 is up, line protocol is up (connected) Hardware is EtherChannel, address is 1cdf.0f82.1607 (bia 1cdf.0f82.1607) Description: EC to xxxx MTU 1500 bytes, BW 2000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec)
[Code]...
How I can attempt to identify what traffic is being dropped?
I am seeing Interface output drops that appera to be incorrect. When I do "Show Interface gi1/0/20", I will get interface output drops of "4294961382". But, when I do the same command again it shows "0" drops. Is this a reporting error? I am ruinning c3750-ipservicesk9-mz.122-58.SE.bin on a 3750 stack with 2 switches in the stack. [code]
we have two 6509E, as our core switches. Recently I noticed that on some connections I have a high output queue drop rate.
These 4 x 2 interfaces (gigabit) are connected to our blade encolure, consisting of 4 x WS-CBS3120X-S. The utilization of the links is really quite low, when I see the increase of the drops. (~=60Mbps). All the links are fiber (SFP) and the distance between the core switches and the enclosure is about 15-20m.
I am not aware of any service degradation on the part of the servers. No CRCs, collisions etc, on the interfaces, apart from the drops.
The line card is a WS-X6748-SFP, but other interfaces don't seem to be experiencing any problems.
I have a few 24-port Cisco 2960G Switches (model WS-C2960G-24TC-L) that I upgraded to IOS Release 15.0(1)SE2 using the web interface. I am now trying to upgrade those switches with the new release, 15.0(1)SE3, however I seem unable to do it, I have tried this on two switches so far, both have been upgraded to SE2 just a couple months ago or so, and both of them will not accept the SE3 upgrade, basically, I can select the tar file in the web browser and click "Upgrade" but when I do the status never changes from "Loading the tar file to the switch". I have tried multiple times from multiple computers using many different web browsers, including IE6 which is listed as supported. I have let it go for as long as 1.5 hours but to no avail.I also had a few idential switches here that had never been upgarded to SE2, I have had no problems loading SE3 onto them using the same method so it would seem that the tar file I have downloaded is valid.
We're having kind of a problem with our Catalyst 4507r switches. If we do a "show interface" command we're getting a lot of "Total output drops" on some of our interfaces. It seems to be most of the time on the same vlan.I was wondering if it has got something to do with QOS or queue selection As we don't have any QOS markings configured, is it possible that all traffic is using only one of the four tx queue's?
We are receiving a large amount of output drops on 4 interfaces that connect to microwave wireless.This is playing up with our Management system. Saw a bug report but that was for 3750, not the IOS version but was a similar issue. [code] The output errors tend to happen at the same time. All ports are trunks however there are other trunks on the switch that are not having these issues. [code]
I recently changed jobs and at the new location we are primarily running Catalyst 2960G series switches with the exception of one 3750. All of the switches are setup in a cluster with the 3750 being the cluster master. My question is what is the benefit of switch clustering? The entire network seems to be a bit over engineered for the our needs and I am hoping to scale it back a bit. For example, the the network was setup with VOIP QoS when there were no plans to even use VOIP. Also what procedures would I want to follow to disable the cluster to avoid any major outages? Assuming there is no real need for a cluster.
I'm trying to decide what switch to use as a core for 500 users. I'm currently looking at either 2 x 3750X stacks or 2 x 4500s with dual SUPs and PSUs, both options will provide the number of switchports required without the need for additonal access layer swiches. Which switch option is best to go for here? All of our services will be located in our data centre which will be connected using 2 1000Mbps MPLS circuits. I wont need any advanced L3 features and we are not likley to scale over 450 users. Also is it ok to use the dual switch stacks or chassis to provide the collapsed core/access layer or is it best to have a dedicated core (using one of the above options with less switchports) and having a dedicated accesss layer using 2960Gs for example. Our structured cabling terminates in a single comms room so we wont need to distribute switches throughout the office.
i had made a software upgarde on the switch 2960G series have no any passwords, when I fished the upgrade process after rebooting the device i found it need a UserPw to access device manager. i tried to use the default PW "cisco" but it dosen't work too.. after that i tried the password recovery process to rest the PW, but noway, but now i have addition problem, when i try the cmd orders "flash_init , load_helper , dir flash" to beginning the password recovery process it shows the following:
The system has been interrupted prior to initializing theflash filesystem. The following commands will initializethe flash filesystem, and finish loading the operatingsystem software:
because I tried to install the IOS by Xmodem to reload the missing flash file.After finsh the TAR file loading and reboot the switch.......the LEDs of mode and Giga ports are lighted amber and not blinking, i tried many times to follow the steps to connect the switch by the emulator and consol cable by holding mode button and connecting the power cable at same time the device does not work, the switch now still not blinking, now i try to read and understand how can i remove the corrupted files and install a new IOS for this switch?What shall i do.
I have used all the ports on my 24 port 2960G and need to extend it with another 2960G. These switches do not have trunk ports so what is the best way to stack them and have all 5 vlans on both switches.Can I just use a port Channel trunk etherchannel ?
I have a Cisco 2960G switch and one of the ports was configured with srr-queue bandwidth limit 90 - I need to remove this bandwidth limiting from this interface. [code]
I have a requirement to monitor downstream data feed from a remote site and feed it to multiple destination devices for recording. The source data will be fed into a port on a Cisco 2960G switch then, using the monitor function, be forwarded to multiple interfaces. This works fine for normal Etherent II traffic. We tried a test using a device that generates IEEE 802.3 Raw packets ('type' field is used as a 'length' field) but found that while the traffic appeared to be accepted by the input port with no errors it was not forwarded to the destination ports, even when using the monitor function. I did try the 'encapsulation replicate' feature with no luck. It does not forward these packets even if I set all the ports into a common VLAN and let the switch just perform a normal switch function (non monitor).
if it is possible to get the IEEE 802.3 raw packets to pass through the switch and if it is, how to or what I need to do to make it work?
I have a 48 port 2960 switch with 2 10/100 ports ( fa0/46-47) setup in an etherchannel with a 2950 48 port switch. I am getting total output drops on port fa0/47. [code]
I've been fighting what seems to be an increased number of outqueue drops on our core stack and edge switches for the last 3 or 4 weeks.(The core consists of a stack of 5 3750s in 32-gig stack mode. The wkgrp switches are 3560s. all are at 12.2.52) The wkgrp switches are directly connected to users. We use Nortel IP phones with the phone inline with the user PC. auto-neg to 100/full. [code] However I have tried turning off QOS on a couple of workgroup switches (no mls qos, but left individual port configurations the same) but am still seeing drops.Since I have disabled qos on the switches in question (no mls qos) (not the core tho) I am presuming these commands have no affect on the switch operation and therefore cannot be related to the problem. With QOS turned off one would presume that it is general congestion - especially at the user edge where busy PC issues might contribute. So I wanted to see if I could see any instances of packets in the output queues building up.
I wrote some scripts and macros that essentially did a snapshot of 'show int' every 20 seconds or so, and looked for instances of 'Queue: x/' where x was greater than zero.What I found after several days of watching the core stack, and a few of the workgroup switches that are most often displaying the behavior, was that I NEVER saw ANY packets in output queues. I often saw packets in Input queues for VLAN1, once in a great while I would see packets on input queues for fa or Gi interfaces, but NEVER on output queues. [ code] Additionally, when I look (via snmp) at interface utilization on interfaces showing queue drops (both core and wkgroup), they are occurring at ridiculously low utilization levels (as low as 4 to 8%). I've tried to look for microbursts between the core and a wkgroup switch where the core interface was experiencing drops, but haven't seen any (using observer suite). [code] While the queue-drop counts aren't critically high at this point, they are happening more frequently than in the past and I would like to understand what is going on... In most cases, no error counters are incrementing for these interfaces. Is there some mechanism besides congestion that could cause output queue drops?
I am unable to access a series of switches connected together through a management vlan. I receive the message "The server xx.xx.xx.xx at level_15_access requires a username and password." Entering the username and password fails and the same username and password message returns. I am able to ssh into the switch with the username and password that fails trying to access the switch with the browser.
How can I check the username and password for access with the browser?
I am trying to monitor switch performance. Is there a good way to monitor switch performance with the command line interface?
I have a connection that is loosing packets, my show interface output below summarises the interface where i believe the problem is occuring. My Hardware is 6509 running 12.2
