05-21-2012 12:34 AM
Hello all,
Cisco does it again...
[1] How can i see if a port has autonegotiated to a certain speed and duplex, and not been configured for a fixed speed or duplex ?
I am trying to determine how the server connected to this port is configured (can be 1000 fixed, or auto-neg)
Eth125/1/20 SRV xxxx S connected 1000 full 1000 --
The port config is:
interface Ethernet125/1/20
description SRV xxxx S
switchport access vlan 1000
spanning-tree guard root
So, I assume this one has autonegotiated ?
Where is the a-full a-1000 in the sh int status then ?
I have to use the command:"sh run int eth125/1/20 all" ?
interface Ethernet125/1/20
description SRV xxxx S
lacp port-priority 32768
lacp rate normal
lldp transmit
lldp receive
no switchport block unicast
no switchport block multicast
no hardware multicast hw-hash
cdp enable
switchport
switchport mode access
no switchport dot1q ethertype
no switchport priority extend
switchport access vlan 1000
spanning-tree port-priority 128
spanning-tree cost auto
spanning-tree link-type auto
spanning-tree port type edge
spanning-tree bpduguard enable
spanning-tree guard root
no spanning-tree bpdufilter
speed auto
duplex auto
flowcontrol receive off
flowcontrol send on
link debounce
no beacon
snmp trap link-status
logging event port link-status default
logging event port trunk-status default
mdix auto
no shutdown lan
load-interval counter 1 30
load-interval counter 2 300
no load-interval counter 3
no shutdown
So, it must have autonegotated, but it is not clear from "sh int status"
sh int eth125/1/20
Ethernet125/1/20 is up
Hardware: 100/1000 Ethernet, address: 0007.7daf.9f15 (bia 0007.7daf.9f15)
Description: SRV xxxx S
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA
Port mode is access
full-duplex, 1000 Mb/s -> no indication of auto-neg either
Beacon is turned off
Input flow-control is off, output flow-control is on
Switchport monitor is off
EtherType is 0x8100
Last link flapped 2d06h
Last clearing of "show interface" counters 4d15h
30 seconds input rate 80 bits/sec, 10 bytes/sec, 0 packets/sec
30 seconds output rate 1224 bits/sec, 153 bytes/sec, 1 packets/sec
Load-Interval #2: 5 minute (300 seconds)
input rate 104 bps, 0 pps; output rate 1.19 Kbps, 1 pps
RX
0 unicast packets 66859 multicast packets 0 broadcast packets
66859 input packets 5616156 bytes
0 jumbo packets 0 storm suppression packets
0 giants 0 input error 0 short frame 0 overrun 0 underrun
0 watchdog 0 if down drop
0 input with dribble 0 input discard
0 Rx pause
TX
4886 unicast packets 487748 multicast packets 360719 broadcast packets
853353 output packets 97647243 bytes
0 jumbo packets
0 output errors 0 collision 0 deferred 0 late collision
0 lost carrier 0 no carrier 0 babble
0 Tx pause
3 interface resets
[2] Do the N2K ports even support auto duplex and half duplex ??
sh int eth125/1/20 cap
Ethernet125/1/20
Model: N2K-C2248TP-1GE
Type (Non SFP): --
Speed: 100,1000,auto
Duplex: full -> doh ? no auto ? no half ? only full supported ?
Trunk encap. type: 802.1Q
Channel: yes
Broadcast suppression: percentage(0-100)
Flowcontrol: rx-(off/on),tx-(off/on)
Rate mode: none
QOS scheduling: rx-(6q1t),tx-(1p6q0t)
CoS rewrite: no
ToS rewrite: no
SPAN: yes
UDLD: no
Link Debounce: yes
Link Debounce Time: yes
MDIX: no
Pvlan Trunk capable: yes
TDR capable: no
Port mode: Switched
FEX Fabric: no
POE capable: no
[3] Once speed is configured, is autonegotiation disabled maybe ?
interface Ethernet125/1/12
description SRV xxxxx S
switchport access vlan 1000
spanning-tree guard root
speed 100
I am getting a lot of errors on this interface:
sh int count error
--------------------------------------------------------------------------------
Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize OutDiscards
--------------------------------------------------------------------------------
Eth125/1/12 19101784 30372 0 19132156 0 0
Can only be the case if the other port has been configured 100 full fixed, we would autoneg to 100 half then ? However, how can i see ?
sh run int Eth125/1/12 all
interface Ethernet125/1/12
description SRV xxxxx S
lacp port-priority 32768
lacp rate normal
lldp transmit
lldp receive
no switchport block unicast
no switchport block multicast
no hardware multicast hw-hash
cdp enable
switchport
switchport mode access
no switchport dot1q ethertype
no switchport priority extend
switchport access vlan 1000
spanning-tree port-priority 128
spanning-tree cost auto
spanning-tree link-type auto
spanning-tree port type edge
spanning-tree bpduguard enable
spanning-tree guard root
no spanning-tree bpdufilter
speed 100
duplex auto
flowcontrol receive off
flowcontrol send on
link debounce
no beacon
snmp trap link-status
logging event port link-status default
logging event port trunk-status default
mdix auto
no shutdown lan
load-interval counter 1 30
load-interval counter 2 300
no load-interval counter 3
no shutdown
sh int eth125/1/12
Ethernet125/1/12 is up
Hardware: 100/1000 Ethernet, address: 0007.7daf.9f0d (bia 0007.7daf.9f0d)
Description: SRV xxx S
MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec,
reliability 230/255, txload 16/255, rxload 1/255
Encapsulation ARPA
Port mode is access
full-duplex, 100 Mb/s
--> mmm , doesn't seem the case, it shows "full" duplex, if it is full duplex auto-neg, then the other side is also in auto-neg, and errors can't be happening. Thanks for the inconsistency....
sh version
Software
BIOS: version 1.3.0
loader: version N/A
kickstart: version 5.0(3)N2(1)
system: version 5.0(3)N2(1)
BTW: it seems TDR cable diagnostics can only be run on N5K ports, not N2K ports (even if they are "ethernet"..):
test cable-diagnostics tdr interface eth125/1/12
TDR tests can be run only on ethernet ports
regards,
GN
Solved! Go to Solution.
05-23-2012 05:48 AM
Hello GN
2248/2224 FEX does auto-negotiate speed to either 100Mbps or 1000Mbps depending on what the far end is advertising. For duplex, the FEX only supports full duplex.
So if you hard code speed to 100 on the FEX and auto-negotiating on the far end, the far end autonegotiating device would do 100/half.
24-10-4948-1#sh run int gigabitEthernet 1/1
Building configuration...
Current configuration : 193 bytes
!
interface GigabitEthernet1/1
description ***used by prkrishn***
no switchport
ip address 1.1.1.100 255.255.255.0
logging event link-status
end
24-10-4948-1#sh int gigabitEthernet 1/1 status
Port Name Status Vlan Duplex Speed Type
Gi1/1 ***used by prkrish connected routed a-half a-100 10/100/1000-TX
24-10-4948-1#
GC-TAC-EFT-5596-A(config-if)# sh run int eth109/1/1
!Command: show running-config interface Ethernet109/1/1
!Time: Wed May 23 08:41:15 2012
version 5.2(1)N1(1)
interface Ethernet109/1/1
spanning-tree bpdufilter enable
speed 100
GC-TAC-EFT-5596-A(config-if)#
GC-TAC-EFT-5596-A(config-if)# sh int ethernet 109/1/1 counters errors
--------------------------------------------------------------------------------
Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize OutDiscards
--------------------------------------------------------------------------------
Eth109/1/1 4 1 0 5 0 0
--------------------------------------------------------------------------------
Port Single-Col Multi-Col Late-Col Exces-Col Carri-Sen Runts
--------------------------------------------------------------------------------
Eth109/1/1 0 0 0 0 0 4
--------------------------------------------------------------------------------
Port Giants SQETest-Err Deferred-Tx IntMacTx-Er IntMacRx-Er Symbol-Err
--------------------------------------------------------------------------------
Eth109/1/1 0 -- 0 0 0 0
TDR is not supported on any interface on the Nexus 5000 and the message you see when you try it for FEX interfaces is misleading for sure.
05-23-2012 05:50 AM
Also according to release notes.
If you configure a Cisco Nexus 2248TP port to 100 Mbps instead of autonegotiation, autonegotiation does not occur, which is expected behavior. Both sides of the link should be configured to both hardwired speed or both autonegotiate.
no speed—Autonegotiates and advertises all speeds (only full duplex)
speed 1000—Autonegotiates only for a 802.3x pause
speed 100—Does not autonegotiate; pause cannot be advertised. The peer must be set to not autonegotiate and fix at 100 Mbps (similar to the N2248TP)
For details, see CSCte81998.
05-23-2012 05:48 AM
Hello GN
2248/2224 FEX does auto-negotiate speed to either 100Mbps or 1000Mbps depending on what the far end is advertising. For duplex, the FEX only supports full duplex.
So if you hard code speed to 100 on the FEX and auto-negotiating on the far end, the far end autonegotiating device would do 100/half.
24-10-4948-1#sh run int gigabitEthernet 1/1
Building configuration...
Current configuration : 193 bytes
!
interface GigabitEthernet1/1
description ***used by prkrishn***
no switchport
ip address 1.1.1.100 255.255.255.0
logging event link-status
end
24-10-4948-1#sh int gigabitEthernet 1/1 status
Port Name Status Vlan Duplex Speed Type
Gi1/1 ***used by prkrish connected routed a-half a-100 10/100/1000-TX
24-10-4948-1#
GC-TAC-EFT-5596-A(config-if)# sh run int eth109/1/1
!Command: show running-config interface Ethernet109/1/1
!Time: Wed May 23 08:41:15 2012
version 5.2(1)N1(1)
interface Ethernet109/1/1
spanning-tree bpdufilter enable
speed 100
GC-TAC-EFT-5596-A(config-if)#
GC-TAC-EFT-5596-A(config-if)# sh int ethernet 109/1/1 counters errors
--------------------------------------------------------------------------------
Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize OutDiscards
--------------------------------------------------------------------------------
Eth109/1/1 4 1 0 5 0 0
--------------------------------------------------------------------------------
Port Single-Col Multi-Col Late-Col Exces-Col Carri-Sen Runts
--------------------------------------------------------------------------------
Eth109/1/1 0 0 0 0 0 4
--------------------------------------------------------------------------------
Port Giants SQETest-Err Deferred-Tx IntMacTx-Er IntMacRx-Er Symbol-Err
--------------------------------------------------------------------------------
Eth109/1/1 0 -- 0 0 0 0
TDR is not supported on any interface on the Nexus 5000 and the message you see when you try it for FEX interfaces is misleading for sure.
05-23-2012 05:50 AM
Also according to release notes.
If you configure a Cisco Nexus 2248TP port to 100 Mbps instead of autonegotiation, autonegotiation does not occur, which is expected behavior. Both sides of the link should be configured to both hardwired speed or both autonegotiate.
no speed—Autonegotiates and advertises all speeds (only full duplex)
speed 1000—Autonegotiates only for a 802.3x pause
speed 100—Does not autonegotiate; pause cannot be advertised. The peer must be set to not autonegotiate and fix at 100 Mbps (similar to the N2248TP)
For details, see CSCte81998.
05-24-2012 01:08 AM
ok, i understand now.
But still i feel the output is not consistent:
If a port is configure like
interface Ethernet125/1/12
description SRV xxxxx S
switchport access vlan 1000
spanning-tree guard root
speed 100
exit
the command: "sh run int Eth125/1/12 all"
should read:
speed 100
duplex full
(indicating, no auto-neg, only full supported)
and not
speed 100
duplex auto
(-> still suggesting that autonegotiation is used)
btw, an indication of autoneg in the "sh int eth125/1/20" would also be great :-)
sh int eth125/1/20
Ethernet125/1/20 is up
Hardware: 100/1000 Ethernet, address: 0007.7daf.9f15 (bia 0007.7daf.9f15)
Description: SRV xxxx S
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA
Port mode is access
a-f-dup, a-1000 Mb/s
(-> indicating autoneg is enabled and it has negotiated to the settings above)
instead of
Capabilities should also show
Duplex: full, auto
(instead of just full)
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