Why this basic dot1q configuration is not working ?

[news2010a]

Hi, can you help me on this ?

I am following the configuration from the link below.

From workstation1, I can ping the default the router successfully. However, I can't ping anything from workstation2. My goal is to ping from workstation1 to workstation2 and vice-versa. Can you please suggest how I can troubleshoot this ? Diagram and router, switch config is attached.

http://www.cisco.com/en/US/tech/tk389/tk390/technologies_configuration_example09186a00800949fd.shtml

[glen.grant]

I don't think you can trunk off a router ethernet interface , it has to be a fastethernet interface to trunk I believe. The trunk is obviously not working . If you have a fast ether try that interface , also set the switch to transparent mode.

per docs:

Sample configurations presented in this document can be used on Cisco 2600/3600/4500/4700 series routers with "Fast Ethernet interfaces" or Fast Ethernet network modules. Also, make sure that you are using the Cisco IOS version that supports ISL/802.1Q VLAN trunking.

[bella]

that's only true for ISL trunking. dot1q is working on ethernet interfaces as well

[ethiel]

Well, nothing jumped right out at me, but what if you try this:

on switch:

Create a vlan 3 on the switch.

int fa0/1

switchport trunk native vlan 3

on router:

interface Ethernet0/0.1

encapsulation dot1Q 1

I suspect that it has to do with the native VLAN tagging, but this will quickly prove if I'm barking up the wrong tree. If I am correct, we can then look more into why it wasn't working.

Either way, in real life Cisco generally recommends not using VLAN1 and not using the native VLAN for traffic.

-Eric

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[news2010a]

Ethiel, I noticed that after your suggested vlan 3 creation, I see on the router traffic on vlan ID:1. Before I didn't see that. However, pinging from Workstation2 to 10.10.11.1 and 10.10.10.1 still times out.

Virtual LAN ID: 1 (IEEE 802.1Q Encapsulation)

vLAN Trunk Interface: Ethernet0/0.1

This is configured as native Vlan for the following interface(s) :

Ethernet0/0

Protocols Configured: Address: Received: Transmitted:

IP 10.10.10.1 107 20

Virtual LAN ID: 2 (IEEE 802.1Q Encapsulation)

vLAN Trunk Interface: Ethernet0/0.2

Protocols Configured: Address: Received: Transmitted:

IP 10.10.11.1 38538 67

[ethiel]

That output didn't really come across intact. In show run under e0/0.1, does it still show "native" after the vlan 1 statement? I was trying to get rid of that, but that output seems to be saying VLAN1 is still set to native on the interface. You may have to "no" the command and re-add it without native at the end.

Here is a config that I have working elsewhere. I am not saying using the native VLAN shouldn't work, but I don't ever use it so I'm not as useful troubleshooting it.

interface GigabitEthernet0/0.2

encapsulation dot1Q 2

ip address x.x.x.x x.x.x.x

interface GigabitEthernet0/0.8

encapsulation dot1Q 8

ip address x.x.x.x x.x.x.x

-Eric

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[news2010a]

Yes, the show run output still shows e0/0.1 as 'native'. Then I did a 'no encapsulation dot1Q 1'. I saved the configuration to 'startup config'. When I ran 'show run' again, the 'native' was added back.

Any ideas ?

interface Ethernet0/0

no ip address

half-duplex

!

interface Ethernet0/0.1

encapsulation dot1Q 1 native

ip address 10.10.10.1 255.255.255.0

no snmp trap link-status

!

interface Ethernet0/0.2

encapsulation dot1Q 2

ip address 10.10.11.1 255.255.255.0

no snmp trap link-status

!

[glen.grant]

See previous message , do not believe you can trunk across a standard 10 meg ethernet interface which is what you have on your router must be a fastethernet interface , just because the commands are there does not mean it will work . Router interface needs to be FASTETHERNET" .

[ethiel]

Glen, that is not entirely true. Some documentation claims that, but I know that some 2600s supported trunking on Ethernet ports. I will try to dig up the details. I know because I have/had several that did for my lab.

-Eric

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[news2010a]

Glen, I value your input, but other folks I know also reported they were able to make a C2600 run trunking on 10Mb/s ethernet interfaces.

In addition, let me add that my IOS is version "Enterprise Basic", image c2600-j1s3-mz.123-16.bin. Since I am able to issue the dot1Q command, I am assuming that the image supports the trunking configuration. I hope I am right.Correct if I am wrong. They say I need 'at least' "IP PLus" images. I am not sure whether "Enterprise Basic" is considered more complete than "IP Plus" ? I used the Cisco online tools and I couldn't determine that for sure though...

[glen.grant]

I stand corrected then have never heard or even seen that in a production environment. I would say it is probably an IOS issue then because the config looked correct .

[bella]

show interface capabilities command will show if ingterface is capable to trunk and what protocol may be used for trunking

[bella]

show the output of show int fa0/1 trunk on the switch

[news2010a]

Switch#show int fa0/1

FastEthernet0/1 is up, line protocol is up

Hardware is Fast Ethernet, address is 0004.c1a9.b581 (bia 0004.c1a9.b581)

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

Auto-duplex (Half), Auto Speed (10), 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:01, output hang never

Last clearing of "show interface" counters never

Queueing strategy: fifo

Output queue 0/40, 0 drops; input queue 0/75, 0 drops

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 2000 bits/sec, 5 packets/sec

16 packets input, 4162 bytes

Received 10 broadcasts, 0 runts, 0 giants, 0 throttles

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

0 watchdog, 9 multicast

0 input packets with dribble condition detected

266 packets output, 14208 bytes, 0 underruns

0 output errors, 0 collisions, 2 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

Switch#

[Adam Frederick]

News2010A:

Issue "show interface fa0/1 trunk" and "show interface fa0/1 switchport" and copy results.

Adam