Not Link port switch 2940 and 2950

[r-barbosa]

Hi all.

I got a switch 2940 and plugged in my 2950 switch but it did not link the port did not signal. I have never had problems with cisco switches, here are the firmware versions for each. And strange not to link to the port the strange thing is that if I connect a notebook in the port it of the link. Another interesting test is if I connect the 2940 on a 2960 link but it shows up in the mismatch speed logs. I already tried setting the speed as speed 100 and full duplex without success too.Has anyone had any idea what it is?

version 2940

Cisco Internetwork Operating System Software
IOS (tm) C2940 Software (C2940-I6Q4L2-M), Version 12.1(22)EA10b, RELEASE SOFTWARE (fc1)

System returned to ROM by power-on
System image file is "flash:/c2940-i6q4l2-mz.121-22.EA10b/c2940-i6q4l2-mz.121-22.EA10b.bin"

Last reset from system-reset
Running Standard Image
8 FastEthernet/IEEE 802.3 interface(s)
1 Gigabit Ethernet/IEEE 802.3 interface(s)

Version 2950

Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA9, RELEASE SOFTWARE (fc1)

nemesis uptime is 4 days, 4 hours, 24 minutes
System returned to ROM by power-on
System image file is "flash:c2950-i6k2l2q4-mz.121-22.EA9"

cisco WS-C2950T-24 (RC32300) processor (revision J0) with 19958K bytes of memory.

Last reset from system-reset
Running Enhanced Image
24 FastEthernet/IEEE 802.3 interface(s)
2 Gigabit Ethernet/IEEE 802.3 interface(s)

[Dennis Mink]

can you check the switchport status (show int xyz switchport) to see if spanning tree is actually forwarding traffic and is not in error disable mode??

cheers

[r-barbosa]

Hi follow output command

2940# show interfaces gigabitEthernet 0/1 switchport
Name: Gi0/1
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Appliance trust: none

2940# optimus#show errdisable detect
ErrDisable Reason Detection status
----------------- ----------------
udld Enabled
bpduguard Enabled
security-violatio Enabled
channel-misconfig Enabled
psecure-violation Enabled
dhcp-rate-limit Enabled
unicast-flood Enabled
vmps Enabled
pagp-flap Enabled
dtp-flap Enabled
link-flap Enabled
gbic-invalid Enabled
loopback Enabled
dhcp-rate-limit Enabled
unicast-flood Enabled
2940#
2940#
2940#show errdisable flap-values
ErrDisable Reason Flaps Time (sec)
----------------- ------ ----------
pagp-flap 3 30
dtp-flap 3 30
link-flap 5 10
2940#show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
udld Disabled
bpduguard Disabled
security-violatio Disabled
channel-misconfig Disabled
vmps Disabled
pagp-flap Disabled
dtp-flap Disabled
link-flap Disabled
psecure-violation Disabled
gbic-invalid Disabled
dhcp-rate-limit Disabled
unicast-flood Disabled
loopback Disabled

Timer interval: 300 seconds

Interfaces that will be enabled at the next timeout:

2940#


2940#show spanning-tree interface gigabitEthernet 0/1
no spanning tree info available for GigabitEthernet0/1
2940#


--------------------------------------------------------------

2950# show interface gigabitEthernet 0/1 switchport
Name: Gi0/1
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk private VLANs: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
2950#

2950#show errdisable detect
ErrDisable Reason Detection status
----------------- ----------------
udld Enabled
bpduguard Enabled
security-violatio Enabled
channel-misconfig Enabled
psecure-violation Enabled
dhcp-rate-limit Enabled
unicast-flood Enabled
vmps Enabled
pagp-flap Enabled
dtp-flap Enabled
link-flap Enabled
gbic-invalid Enabled
loopback Enabled
dhcp-rate-limit Enabled
unicast-flood Enabled


2950#show errdisable flap-values
ErrDisable Reason Flaps Time (sec)
----------------- ------ ----------
pagp-flap 3 30
dtp-flap 3 30
link-flap 5 10


2950#show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
udld Disabled
bpduguard Disabled
security-violatio Disabled
channel-misconfig Disabled
vmps Disabled
pagp-flap Disabled
dtp-flap Disabled
link-flap Disabled
psecure-violation Disabled
gbic-invalid Disabled
dhcp-rate-limit Disabled
unicast-flood Disabled
loopback Disabled

Timer interval: 300 seconds

Interfaces that will be enabled at the next timeout:

2950#


2950#show spanning-tree interface gigabitEthernet 0/1
no spanning tree info available for GigabitEthernet0/1

2950#

Any idea?

[Leo Laohoo]

Cable to connect both switches should be cross-over.

[r-barbosa]

why are the two gigabitEthernet interface needs to cross? but I still tested with cross and it did not work. A friend told me that he already had a problem with distinct IOS versions that the encapsulation is not compatible, have you heard anything like it?

[Leo Laohoo · Accepted solution]

---

@r-barbosa wrote:
why are the two gigabitEthernet interface needs to cross? 

---

This is basic Networking 101.  Neither 2940 nor 2950 can support MDI/MDI-X so cross-over cable is required to interconnect them. 

---

@r-barbosa wrote:
A friend told me that he already had a problem with distinct IOS versions that the encapsulation is not compatible, have you heard anything like it?

---

Your friend is misinformed.  2940 and 2950 both belong to the same family of switches and they only support 802.1q trunking and neither can support ISL. 

Can you move the crossover to the FastEthernet ports of both switches and see if the ports come up?

[r-barbosa]

Thanks Leo.

Its works. I put the cable cross and it worked perfectly. And what you said 2940 and 2950 do not support MDI / MDIX. I just had to set the duplex to full manual and it worked. Thank you very much

Regards

[Leo Laohoo]

Thanks for taking the time to provide us with the update. :)