I found a good document describing "speed nonegotiate" command: http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/intrface.html#wp1040549
First of all, the name of the command seems to be as misleading as possible :) It does not negotiate port speed. It should be "link nonegotiate" or something similar. Looks like it's available only in case of optical ports and sent information is flow-control parameters, remote fault information and duplex information. As I understand, those checks are implemented on Cisco gear only. For example if I set "speed nonegotiate" on port Gi2/2 on switch port(in other words it operates as non-Cisco optical port): ! interface GigabitEthernet2/2 speed nonegotiate end ..and port Gi4/1 has default configuration: ! interface GigabitEthernet4/1 end ..then port Gi2/2 is "connected" while Gi4/1 is "notconnect" which makes sense as Gi2/2 is not expecting information negotiated during link negotiation. regards, Martin 2013/2/8, Martin T <[email protected]>: > Hi, > > one can apply "speed nonegotiate" command under interface > configuration mode in case of optical SFP/GBIC. Looks like this > command is supported only in case of optical transceivers. For example > I have a Cisco WS-C3750G-12S switch and if I insert copper SFP to port > Gi1/0/2, I do not have "speed nonegotiate" command available: > > C3750(config-if)#do sh int Gi1/0/2 status > > Port Name Status Vlan Duplex Speed Type > Gi1/0/2 notconnect 1 auto auto > 10/100/1000BaseTX SFP > C3750(config-if)#speed ? > 10 Force 10 Mbps operation > 100 Force 100 Mbps operation > 1000 Force 1000 Mbps operation > auto Enable AUTO speed configuration > > C3750(config-if)#speed > > > Now if I remove the copper SFP and insert optical SFP or do not insert > nothing at all, I have "speed nonegotiate" command available: > > C3750(config-if)#do sh int Gi1/0/2 status > > Port Name Status Vlan Duplex Speed Type > Gi1/0/2 notconnect 1 auto auto > 1000BaseLX SFP > C3750(config-if)#speed ? > nonegotiate Do not negotiate speed > > C3750(config-if)#speed > > > In addition, I have one one optical SFP with modified EEPROM so that > it appears as an copper SFP to the switch and thus "speed nonegotate" > command is not available: > > > C3750(config-if)#do sh int Gi1/0/2 status > > Port Name Status Vlan Duplex Speed Type > Gi1/0/2 notconnect 1 auto auto > 10/100/1000BaseTX SFP > C3750(config-if)#speed ? > 10 Force 10 Mbps operation > 100 Force 100 Mbps operation > 1000 Force 1000 Mbps operation > auto Enable AUTO speed configuration > > C3750(config-if)#speed > > > Same behavior can be seen on Cisco 4500 platform where optical > GBIC's(on WS-X4306-GB module) support "speed nonegotiate" command and > copper GBIC's(WS-G5483) do not. 1000BASE-SX or 1000BASE-LX10 support > only 1GigE mode so there should be nothing to negotiate in terms of > speed.. > > In practice, I have used "speed nonegotiate" command in case I connect > Cisco optical SFP to a media-converter and I have heard that > connecting optical transceivers to non-Cisco gear (sometimes) require > "speed nonegotiate" command. Otherwise link will not come up. > > Am I correct, that "speed nonegotiate" is available only on optical > transceivers? What is the history behind "speed nonegotiate" command? > What information is exchanged and expected by Cisco device if "speed > nonegotiate" command is not applied? > > > > regards, > Martin > _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
