Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Cisco > Router on the stick configuration problem

Reply
Thread Tools

Router on the stick configuration problem

 
 
Guan Foo Wah
Guest
Posts: n/a
 
      10-23-2005
Hi all,

I have some problem configuring router on the stick. Basically, here is the
configuration on my router 2612 router running on 12.2(31) IP Plus. This
router is attached to a Cat 2950 and its attached port is configured as
"switchport mode trunk"

interface ethernet0/0
no ip address
half-duplex
interface ethernet0/0.1
encapsulation dot1Q 1 native
ip address 10.0.0.41 255.255.0.0
interface ethernet 0/0.2
encapsulation dot1Q 2
ip address 10.16.0.41 255.255.0.0

Members in vlan 2 can ping 10.16.0.41 but members in vlan 1 cannot ping
10.0.0.41. If I change the configuration to this....
interface ethernet0/0
ip address 10.0.0.41 255.255.0.0
half-duplex
interface ethernet 0/0.2
encapsulation dot1Q 2
ip address 10.16.0.41 255.255.0.0

Members in vlan 1 have no problem pinging to 10.0.0.41 and members in vlan 2
have no problem pinging 10.16.0.41. Any idea on what is happening? Both
configuration are supposed to be valid and workable and but apparently the
upper configuration is not working all all. Thanks in advance.





 
Reply With Quote
 
 
 
 
Cen
Guest
Posts: n/a
 
      10-24-2005
Most likely you have encountered a Cisco bug (Bug ID CSCds42715). Refer to
http://www.cisco.com/warp/public/473/50.shtml for more info.




"Guan Foo Wah" <(E-Mail Removed)> wrote in message
news:435ba5ed$(E-Mail Removed)...
> Hi all,
>
> I have some problem configuring router on the stick. Basically, here is
> the configuration on my router 2612 router running on 12.2(31) IP Plus.
> This router is attached to a Cat 2950 and its attached port is configured
> as "switchport mode trunk"
>
> interface ethernet0/0
> no ip address
> half-duplex
> interface ethernet0/0.1
> encapsulation dot1Q 1 native
> ip address 10.0.0.41 255.255.0.0
> interface ethernet 0/0.2
> encapsulation dot1Q 2
> ip address 10.16.0.41 255.255.0.0
>
> Members in vlan 2 can ping 10.16.0.41 but members in vlan 1 cannot ping
> 10.0.0.41. If I change the configuration to this....
> interface ethernet0/0
> ip address 10.0.0.41 255.255.0.0
> half-duplex
> interface ethernet 0/0.2
> encapsulation dot1Q 2
> ip address 10.16.0.41 255.255.0.0
>
> Members in vlan 1 have no problem pinging to 10.0.0.41 and members in vlan
> 2 have no problem pinging 10.16.0.41. Any idea on what is happening? Both
> configuration are supposed to be valid and workable and but apparently the
> upper configuration is not working all all. Thanks in advance.
>
>
>
>
>



 
Reply With Quote
 
 
 
 
Surfraz Surfraz is offline
Junior Member
Join Date: Jan 2010
Posts: 1
 
      01-05-2010
Why did you configure "half duplex"...

This may be the reason of why only one vlan can ping in the trunk, as its using shared wire

If you configure full duplex on the subinterface, it should work
 
Reply With Quote
 
donjohnston donjohnston is offline
Member
Join Date: Jun 2008
Posts: 38
 
      01-15-2010
I have had more problems trying to trunk an ethernet (10m) port than not.

My opinion is, use a fastethernet interface.
 
Reply With Quote
 
joshstout joshstout is offline
Junior Member
Join Date: Nov 2010
Posts: 1
 
      11-07-2010
The reason for this behavior is that 2950 switches do not tag the native vlan as they use DOT1q by default.

If you issue a "debug arp" on the router in this scenario while pinging from the router to a device on the switch in vlan 1... you can see that the router responds with a message stating it did in fact recieve an arp reply but filtered it as it came in on the main interface instead of the sub-interface.

This again, is because the switch did not tag the arp reply and thus it arrives on the physical interface.

While all of this may make sense, I am confused as to why the router doesn't logically route the untagged traffic into its interface tagged with the "native" keyword.

Hope this helps,
 
Reply With Quote
 
nover nover is offline
Junior Member
Join Date: Nov 2010
Posts: 5
 
      11-15-2010
thanks for useful information...
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
CatOS router on a stick configuration T0nyD Cisco 3 01-25-2010 07:21 PM
Differences between Sony Memory Stick & memory Stick Pro vs Memory Stick Duo? zxcvar Digital Photography 3 11-28-2004 10:48 PM
Memory stick pro is cheaper than normal memory stick fanfaron Digital Photography 2 06-07-2004 03:27 PM
Sony DSC-U30 Memory Stick vs. Memory Stick Pro Barry Lovelace Digital Photography 1 02-11-2004 09:23 PM
Sony Memory Stick Pro vs Standard Memory Stick jwv Digital Photography 13 07-19-2003 12:04 AM



Advertisments