I have the following issue;
I am getting a duplex mismatch between a Cisco 2960 TT-L Switch running IOS 12.2(35) LAN Base Image (Gig0/1) and a Cisco 6506 Switch running IOS 12.2(33)SXH Adv IP Services (Gig2/19).
I have tried several combinations of the duplex/speed settings on both sides but the only that works is setting duplex/speed AUTO on the Cisco 2960 which ends up autonegotiating to HALF duplex and 100Mbps.
What cou;d be the issue? IOS bugs?
I have upgraded the Cisco 2960 Switch to version 12.2(52). The interfaces are now at FULL duplex but cannot negotiate to 1000Mbps.
Ports are on default;
switchport mode access
switchport access vlan zzz
ip address x.x.x.x y.y.y.y
Is there only cable between those 2 boxes, or is there some convertor (fiber optic)?
Also you can try speed nonegotiate command on both sides.
It is generally advised you use auto on both sides for gigabit. If they are not negotiating gig then I would take a serious look at the cabling . Unlike fastether which takes 2 pairs you must have 8 good wires in the entire path between the 2 devices in order to negotiate gig as gig uses all 8 wires to achieve gig speeds . Even 1 bad wire out of the 8 it will not negotiate gig . Make sure speed negotation is actually turned on for the 6500. you can check this with the following counterintuitive command
no speed nonegotiate . Verify with the command Good info for explaining the different states for gig port settings. http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/intrface.html#wp1020621
show interfaces GigabitEthernet slot/port transceiver properties
On the 2960 switch the "dual purpose" uplinks need to be manually configured with "media-type" to be able to set speed/duplex. Default would not allow setting these 2 attributes.
switchport mode trunk
GigabitEthernet0/1 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is
Description: Uplink to Cat01
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 100Mb/s, link type is auto, media type is 10/100/1000BaseTX