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Router sub interface 1

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lobo66

IS-IT--Management
Joined
Nov 12, 2002
Messages
106
Location
US
have a 2611 with dual eth 0/0 and eth 0/1

try to connect a trunk to eth 0/0 via a sub interface 0/0.1 but it will not allow me to ecap do1q, is this not possible on a eth int only on a fa port?

THX
 
I beleive your a correct in that dot1q will only work on fast ethernet port.
 
you know of any work arounds for this?
 
Have some of those routers myself. Not found a work around for this. Our 2611 routers are scheduled to be replaced with Cisco 1841 ISR routers within the next 6 months. You could get a Cisco 3620 with a 2 port fast ethernet module on Ebay for a good price and that should do it. Have not tried it with that series of router and if you consider it then double check that it supports trunking before purchase. I know that the 1841 does though.
 
A cisco 2621 might also be a good choice as it has 2 on board fast ethernet ports.
 
THX all have a 3660 I can use just setting up a test lab to the internet...
 
802.1Q trunk support became available in the 2611 with version 12.2T. If you can somehow find 12.2(15)T somewhere, you should be good to go.
 
Thanks for the info....tested on 2611 with 12.3(13) and it does indeed allow it.
 
I tried settin my 2611 to dot1q and the sub-interface accested the command. It is connected to a 2950 switch port and connot communicate with each other.

Switch
interface FastEthernet0/7
switchport mode trunk
switchport nonegotiate
speed 10
duplex full
mls qos trust cos
macro description cisco-router
spanning-tree portfast trunk
spanning-tree bpduguard enable

Router
interface ethernet0/1
no ip address
full-duplex
interface ethernet0/1.1
encapsulation dot1Q 1 native
ip address 192.168.26.28 255.255.255.0
no snmp trap link-status

IP of vlan 1 on switch is 192.168.26.34 255.255.255.0
 
What feature set are you using on the router?
 
System image file is "flash:c2600-ik9o3s3-mz.123-13.bin"
IP/FW/IDS PLUS IPSEC 3DES BASIC
 
Switch is WS-C2950-24 with:
C2950 EI AND SI IOS IMAGE
c2950-i6q4l2-mz.121-22.EA5a.bin
 
Is it possible that the following is the problem I am having:
The Cisco Catalyst 2950SX-48, 2950T-48, 2950SX-24, 2950-24 and 2950-12 switches (Figures 1-5) are available only with the Standard Image (SI) software for the Cisco Catalyst 2950 Series. They cannot be upgraded to the Enhanced Image (EI) software.
 
JOAMON,
The 2950 w/standard image should work just fine.

I know this sounds simple, and I apologize if this offfends, but did you issue a "no shut" on the int e0/1?

Did you try "no ip route-c" for the sub interface?
 
As you can see from the previous post the interfaces are not shutdown. No I did not try no ip route-c on the sub-interface but will do so.
 
no ip route-cache had no effect. Can see other devices via CDP but thats it.
 
I'm inclined to think that something else is wrong. A 2610/11 running 12.2 IP PLUS or better should support 802.1Q. I don't have any guesses as to what might be wrong, though.
 
Neither do I. Shutdown and removed sub-interface, apples IP to ethernet0/1 and work fine. Try to set trunking and nadda....wierd.
 
That is weird. I don't even have a guess. I'll let you know if I think of something. Is there trunk debugging available on either the router or the switch? Perhaps debugs might tell us why the trunk isn't working.
 
Did you have a native VLAN mismatch? Was that switchport in the correct VLAN before you made it a trunk?
 
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