Re: Unknown protocol drops are increasing - Page 2

sathyasav · ‎10-10-2011

Hello,

What is unknown protocol drops because i have a 7200 series router connected to the 4500 series switch and i am able to see these unknown protocol drops getting increased once every 30 sec.

Router -21>sh int gi0/1

GigabitEthernet0/1 is up, line protocol is up

5 minute input rate 7418000 bits/sec, 6212 packets/sec

5 minute output rate 10991000 bits/sec, 5264 packets/sec

1643435459 packets input, 2165307555 bytes, 0 no buffer

Received 28581 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 330098 multicast, 0 pause input

0 input packets with dribble condition detected

1510539932 packets output, 4224476290 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

19009 unknown protocol drops

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier, 0 pause output

0 output buffer failures, 0 output buffers swapped out

sathyasav · ‎10-12-2011

Rick/Andrew,

i tried configuring the command switchport nonegotiate on the interface which is connected to the router and i am getting the belor error and the interface is not taking the command.Please advice what could be thwb cause and how to overcome this.

error message: conflict between nonegotiate and dynamic status

Please reply ASAP...

Richard Burts · ‎10-12-2011

In an early post in this thread you say that the switch port is configured as an access port in vlan 10. But you have given us no other detail about the interface. Perhaps you can post the configuration of the port and the output of show interface on the switch?

I associate the nonegotiate command with etherchannel/trunking. I wonder if the issue might be trying to use that command on an access port?

HTH

Rick

HTH

Rick

andrew.prince · ‎10-12-2011

To echo Rick,

You need to loo at the output of "show interface <> switchport

hopefully you will see something like

Switchport: Enabled

Administrative Mode: static access

Operational Mode: static access

Administrative Trunking Encapsulation: negotiate

Negotiation of Trunking: Off

sathyasav · ‎10-12-2011

Rick/Andrew,

still i am saying that this port is configured as a access port and connected to the router.Please find the switch configuration below.

ASB-BAN-SW21#sh run int fa2/48
Building configuration...

Current configuration : 162 bytes
!
interface FastEthernet2/48
description $$ Connection to WAN-Router $$
switchport access vlan 10
speed 100
duplex full
spanning-tree bpdufilter enable
end

ASB-BAN-SW21#sh run int vl
ASB-BAN-SW21#sh run int vlan 10
Building configuration...

Current configuration : 105 bytes
!
interface Vlan10
description $$ Router-Connectivity $$
ip address 172.18.159.1 255.255.255.248
end

ASB-BAN-SW21#

ASB-BAN-SW21#sh int fa2/48
FastEthernet2/48 is up, line protocol is up (connected)
Hardware is Fast Ethernet Port, address is 5475.d09a.441f (bia 5475.d09a.441f)
Description: $$ Connection to WAN-Router $$
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 16/255, rxload 30/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, link type is auto, media type is 10/100BaseTX
input flow-control is unsupported output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:58, output never, output hang never
Last clearing of "show interface" counters 15:32:37
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 12007000 bits/sec, 5132 packets/sec
5 minute output rate 6448000 bits/sec, 6057 packets/sec
     184969319 packets input, 79402366610 bytes, 0 no buffer
     Received 1026 broadcasts (1026 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 input packets with dribble condition detected
     183063997 packets output, 35048261337 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out
ASB-BAN-SW21#sh int fa2/48 sw
ASB-BAN-SW21#sh int fa2/48 switchport
Name: Fa2/48
Switchport: Enabled
Administrative Mode: dynamic auto
Operational Mode: static access
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: On
Access Mode VLAN: 10 (Router-Connectivity)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
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 Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
ASB-BAN-SW21#

andrew.prince · ‎10-12-2011

Your issue:-

Administrative Mode: dynamic auto

Operational Mode: static access

Negotiation of Trunking: On

Configure

!

interface FastEthernet2/48

switchport mode access

switchport noneg

sathyasav · ‎10-12-2011

Ok Andrew i will do this configuration tommorrow Off production hours and let you know the result.But gefore that one basic question the default switchport mode is dynamic desirable right?then why it is showing dynamic auto in my case.And the next question is why is it necessary to configure the switchport nonegiate on the access port since the access port dont send DTP.

Sathya

andrew.prince · ‎10-12-2011

These various modes are configured using the switchport mode interface command

Switch trunk interfaces support different trunking modes.

Access

Dynamic desirable (default mode on Catalyst 2950 and 3550)

Dynamic auto

Trunk

Non-negotiate

dotq-tunnel (Not an option on the Catalyst 2950.)

switchport mode access - This command puts the interface (access port) into permanent nontrunking mode. The interface will generate DTP frames, negotiating with the neighboring interface to convert the link into a nontrunk link. The interface becomes a nontrunk interface even if the neighboring interface does not agree to the change.

switchport mode dynamic desirable - This command makes the interface actively attempt to convert the link to a trunk link. The interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode. This is the default mode for all Ethernet interfaces. If the neighboring interface is set to the access or non-negotiate mode, the link will become a non-trunking link.

switchport mode dynamic auto – This command makes the interface willing to convert the link to a trunk link if the neighboring interface is set to trunk or desirable mode. Otherwise, the link will become a non-trunking link.

switchport mode trunk – This command puts the interface into permanent trunking mode and negotiates to convert the link into a trunk link. The interface becomes a trunk interface even if the neighboring interface does not agree to the change.

switchport nonegotiate – Prevents the interface from generating DTP frames. You can use this command only when the interface switchport mode is access or trunk. You must manually configure the neighboring interface as a trunk interface to establish a trunk link, otherwise the link will be a non-trunking link.

sathyasav · ‎10-12-2011

Hi Andrew,

here you mentioned the port will become non-trunk.

do you mean it is access(non-trunk)

switchport mode dynamic desirable - This command makes the interface actively attempt to convert the link to a trunk link. The interface becomes a trunk interface if the neighboring interface is set to trunk, desirable, or auto mode. This is the default mode for all Ethernet interfaces. If the neighboring interface is set to the access or non-negotiate mode, the link will become a non-trunking link.

switchport mode dynamic auto – This command makes the interface willing to convert the link to a trunk link if the neighboring interface is set to trunk or desirable mode. Otherwise, the link will become a non-trunking link.

andrew.prince · ‎10-12-2011

What do you think it means? What is a port that is not a trunk?

sathyasav · ‎10-13-2011

It should be a access port....I asked just like that..LOL

Any way it is a very deep discussion....very much useful for me...so one final question.Cant we enable the command switchport nonegiate on the port on which switchport mode dynamic auto and switchport mode dynamic desirable is set already?

SATHYA...