cisco 1900 switch Trunk capability with WS-C3560G-24PS

[srikanth ath]

Hello Expert,

In our production.

The switch interface of 3560 connected to 1900 is configured as access port. and i was asked to make the both the interfaces of 1900 and 3560 as trunk. can i configure as some where i read the switch 1900 doesnt support 802.1q.

Switch 3560 seems to be supported with ISL and .1q

X(config)#int gigabitEthernet 0/27
X(config-if)#switchport trunk en
X(config-if)#switchport trunk encapsulation ?
  dot1q      Interface uses only 802.1q trunking encapsulation when trunking
  isl        Interface uses only ISL trunking encapsulation when trunking
  negotiate  Device will negotiate trunking encapsulation with peer on
             interface
 

If i can i have a document with CLI configuration as this 1900 switch looks weird and im going crazy in understanding the configs.

Thanks,

[Jon Marshall]

The 1900 switch only supports ISL on trunk links as you say.

Here is a link to a document showing how to configure a 1900 connecting to a CatOS switch. Ignore the CatOS switch part -

http://www.cisco.com/c/en/us/support/docs/lan-switching/inter-switch-link-isl/24066-174.html

Jon

[srikanth ath]

Hi 

Thanks for the responses. I went through the Document, but the Switch 1900 doesnt have the Trunk configuration under the interface.

It just has 

X(Config)# Int e 0/1

X(Config-if)#vlan-membership ?

static

dynamic

X# trun?

<cr>

Cisco1912#show trunk ?
A Trunk A
B Trunk B
Cisco1912#show trunk A

[Jon Marshall]

Do you have the Enterprise Edition software ?

Jon

[srikanth ath]

Thanks Jon.

I see it is the Enterprise edition software under sh version.

The Fast ethernets port are trunkable in this switch the rest of the eth 0/1 to 0/24 are not.

but i have no idea on how to trunk this 1900 with 3560 .

The 1900 has these options on, auto, desirable. what option to be selected and respective mode i need to select on the trunk interface of 3560?

1900#sh version
Cisco Catalyst 1900/2820 Enterprise Edition Software
Version V8.00.04
Copyright (c) Cisco Systems, Inc.  1993-1998

1900(config)#int fa 0/26
1900(config-if)#trun
1900(config-if)#trunk?
trunk  trunk-vlan
1900(config-if)#trunk ?
  auto         Set DISL state to AUTO
  desirable    Set DISL state to DESIRABLE
  nonegotiate  Set DISL state to NONEGOTIATE
  off          Set DISL state to OFF
  on           Set DISL state to ON
1900(config-if)#trunk

 

[srikanth ath]

Ok thanks all.

the last thng left to be clarified.

what does trunk on / desirable / auto means in 1900 switches.

[acampbell]

Hi,

Not sure if you saw my last relpy

On the 1900

!
int f0/26
trunk on
!

On the 3560

!
int f0/24
switchport trunk encap isl
switchport mode trunk
!

In answer to your trunk status quey

ON = No negotiation - this prt does not send DTP packets IT IS ALWAYS a TRUNK

DISIABLE = The port initiates DTP and will become trunk if the other end responds, if the other end does not respond the port becomes an access port

AUTO = Like the desrirable BUT the port will not initiate the DTP negotiation, it will only respond.

AUTO to AUTO == NO TRUNK

DESIRABLE to AUTO == TRUNK

DESIRABLE to DESIRABLE == TRUNK

ON to ON == TRUNK

ON to AUTO -- TRUNK

ON to DESIRABLE == TRUNK

Hope this helps
Regards
Alex

[Jan Rolny]

Hi,

please note that you need Enterprise Edition software

• All Ethernet ports support ISL encapsulation. Enterprise Edition software is necessary.

• There is no support for 802.1Q.

• There is support for DTP in ISL only

Best resgards,

Jan

[srikanth ath]

Hi 

Thanks for the responses. I went through the Document, but the Switch 1900 doesnt have the Trunk configuration under the interface.

It just has 

X(Config)# Int e 0/1

X(Config-if)#vlan-membership ?

static

dynamic

X# trun?

<cr>

Cisco1912#show trunk ?
A Trunk A
B Trunk B
Cisco1912#show trunk A

[srikanth ath]

Hi 

Thanks for the responses. I went through the Document, but the Switch 1900 doesnt have the Trunk configuration under the interface.

It just has 

X(Config)# Int e 0/1

X(Config-if)#vlan-membership ?

static

dynamic

X# trun?

<cr>

Cisco1912#show trunk ?
A Trunk A
B Trunk B
Cisco1912#show trunk A

[acampbell]

Hi,

On the 1900

!
int f0/26
trunk on
!

On the 3560

!
int f0/24
switchport trunk encap isl
switchport mode trunk
!

Hope this helps
Regards
Alex