Slow network performance

[Dimuthu Parussalla BWEADM non-std-pwd]

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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