Slow network performance

[Vinny Abello]

This sounds like your switch and host settings are correct so I wouldn't spend too much more time looking at that at this point. I just wanted to mention it to be sure.

Good luck!

Dimuthu Parussalla BWEADM non-std-pwd wrote:
> This is exactly what I did.
> Managed Switch A (2950G)
> 1) both switch and bge/em card set for auto negeotiation
> 2) Both switch and bge/em set for 1000mb full-duplex.
> 
> Managed Switch B (Netgeat GSM7224)
> 1) both switch and bge/em card set for auto negeotiation
> 2) Both switch and bge/em set for 1000mb full-duplex.
> 
> I am seriously running out of options.
> Thanks
> 
> Vinny Abello writes:
>> Although I don't think this is necessarily the cause of your dropouts 
>> as you put it, one must understand the way autonegotiation and manual 
>> speed and duplex work between network gear.
>> For autonegotiation to work, BOTH devices must support 
>> autonegotiation, OR both devices must be set to the same speed and 
>> duplex setting. If one only supports auto and the other does not, you 
>> must NOT set the device that you can manually configure to full 
>> duplex. The auto device will never negotiate at full duplex and fall 
>> back to half when autonegotiation fails, causing a duplex mismatch and 
>> horrible network performance and loss.
>> A very rough set of rules of thumb (YMMV):
>> When connecting to an unmanaged switch, use auto. If your host doesn't 
>> support auto, set it to half-duplex.
>> When connecting to a managed switch, make sure the port is set to auto 
>> and set your system to auto, otherwise force both the switch port and 
>> your host to the same settings. This is required especially if the 
>> host doesn't support auto negotiation and you want to run at full duplex.
>> When connecting to a managed switch, enable portfast or the equivalent 
>> spanning-tree command on the switch port your host is connected to so 
>> it forwards traffic immediately when getting link.
>>
>> So to sum it up, auto only works if both sides speak auto. Auto 
>> negotiation failure falls back to half-duplex!
>> Of course there are all the horror stories where auto negotiation is 
>> evil and that different vendor's implementations don't play nice or 
>> are just completely broken, so always set things to manual or you and 
>> your family will suffer an untimely death... There are so many of 
>> these stories that one would think there has to be some truth to it. 
>> In my own experience, I have never had an issue with auto negotiation 
>> in some ten years of working with a dozen different vendors' 
>> networking gear so I guess I'm lucky... or I just understand how it 
>> interacts with other devices and their capabilities. I still don't 
>> know which exactly.
>>
>> Hope this helps! :)
>>
>> Dimuthu Parussalla wrote:
>>> Hi All,
>>> Apart from random dropout from the network. Our IBM X236 server 
>>> suffers slow
>>> network performance. I've changed the server from CISCO switch to a 
>>> netgear
>>> switch on a test platform. Also tried 1000m full-duplex setup with no 
>>> auto
>>> negotionation on both ends. Still after few days (3-4) server drops the
>>> connection. And while its working I get 90KBps upload/download with ftp
>>> transfers.
>>> I have treid changing BGE network cards to EM (intel 100/1000) still the
>>> same result. Any idea's to nail this problem?
>>>
>>> /etc/sysctl.conf
>>> kern.ipc.maxsockbuf=8388608
>>> kern.ipc.somaxconn=2048
>>> net.inet.tcp.sendspace=3217968
>>> net.inet.tcp.recvspace=3217968
>>> net.inet.tcp.rfc1323=1
>>> #net.inet.tcp.rfc3042=0
>>> net.inet.ip.portrange.hilast=65535
>>> net.inet.ip.portrange.hifirst=49152
>>> net.inet.ip.portrange.last=65535
>>> net.inet.ip.portrange.first=1024
>>> net.inet.tcp.inflight.enable=0
>>>  
>>>
>>> /boot/loader.conf
>>> kern.ipc.nmbclusters=32768
>>>
>>> Interfaces:
>>> em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>>>         options=b<RXCSUM,TXCSUM,VLAN_MTU>
>>>         inet 192.168.1.12 netmask 0xffffff00 broadcast 192.168.1.255
>>>         ether 00:0e:0c:d0:73:3c
>>>         media: Ethernet 1000baseTX <full-duplex>
>>>         status: active
>>> em1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>>>         options=b<RXCSUM,TXCSUM,VLAN_MTU>
>>>         inet 6x.xx.xx.xx netmask 0xffffffc0 broadcast xxx.xxx.xxx.255
>>>         ether 00:0e:0c:9f:f4:5e
>>>         media: Ethernet 100baseTX <full-duplex>
>>>         status: active
>>>  
>>>
>>> Regards
>>> Dimuthu Parussalla
>>>
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