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New Member

router on the stick, and cable V35 question....

Hi !

I'm currently prepared my CCNP BSCI Certification Exam. I own some old Cisco router devices which I use as a small studdy lab. But a lot of them have only on ethernet connector. I would configure those as router on a stick.

When I try to setup ip address on sub-interface I received the following message : "

Configuring IP routing on a LAN subinterface is only allowed if that

subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q, or ISL vLAN."

I try to find how I can configure the interface for ISL encapsulation..... I one documentation on the web I find I should use "encapsulation isl #vlan" command in the sub-interface mode. But in the command listed in the sub-interface mode encapsulation command is not available :


Interface configuration commands:

arp Set arp type (arpa, probe, snap) or timeout

backup Modify backup parameters

bandwidth Set bandwidth informational parameter

bridge-group Transparent bridging interface parameters

carrier-delay Specify delay for interface transitions

cdp CDP interface subcommands

default Set a command to its defaults

delay Specify interface throughput delay

description Interface specific description

exit Exit from interface configuration mode

ip Interface Internet Protocol config commands

llc2 LLC2 Interface Subcommands

mtu Set the interface Maximum Transmission Unit (MTU)

netbios Use a defined NETBIOS access list or enable name-caching

no Negate a command or set its defaults

shutdown Shutdown the selected interface

snapshot Configure snapshot support on the interface

standby Hot standby interface subcommands

timeout Define timeout values for this interface

traffic-shape Enable Traffic Shaping on an Interface or Sub-Interface

on the interface mode I nothing about encapsulation also !!

here is running plate-form :

R2#sh ver

System returned to ROM by reload

System image file is "flash:c1600-oy-mz.121-6.bin"

also with 2500 Cisco router which cable type I can buy to connected them each other by there serial connector ?? (I know this configuration is most ofter use in lab and is not ofter implemented in production network)

could some help me ??

Hall of Fame Super Silver

Re: router on the stick, and cable V35 question....

Hello Christian,

check if the following is supported

int et0/0.10

enc dot1q 10

ip address

the message says that you need to specify to what broadcast domain (Vlan-id) the subinterface is associated.

Actually the subinterface index is one thing the L2 vlan association requires the encapsulation command

eventually verify if

enc isl 10

is supported

if one of the command versions is supported you can have your router on a stick.

the switch port needs to be configured as a L2 trunk with matching encapsulation

int f0/5


switchport trunk enc dot1q

switchport mode trunk

switchport trunk allowed vlan 10,20,30

b) about back to back connection with V.35 you need a DTE cable and a DCE cable.


Hope to help


New Member

Re: router on the stick, and cable V35 question....

Hi !

my router do not support :

int et0/0.10

but support command :

int et0.10

in this sub interface mode, no encapsulation command is support... look like encapsulation ISL is not support on this router... But what I had find bizzard, is why when I try to setup ip address on this same interface router, the errors messages aks me to setup ISL encapsulation on this same interface, what is looklike not supported ??

this a lot for cable description, I will order thoses from my supplier thomorrow...

Re: router on the stick, and cable V35 question....


Your IOS is pretty old. c1600-oy-mz.121-6.bin. As I recall, Ethernet(10Mbps) doesn't support 802.1q encapsulation. It can be done on some code for C25xx or C26xx (Regarding Ethernet(10M). Fastethernet is fine.

However,ISL encapsulation, it doesn't support on C16xx as well. How can I know? Well, here you go :

That is my default homepage on IE. J/K(grin)



New Member

Re: router on the stick, and cable V35 question....

yes I know my IOS is pretty old, I use old devices as a small lab. I don't have the budget to buy new material to complete my CCNP certification by my self !! at the office we don't have access to a lab or production environment on which I can hope to have the necessaily configuration to understanding requirement of the BSCI exam certification....

As I understand router on the stick configuration will be not possible with this IOS version...

Thanks a lot for the like you had provide to me !