Field Notice: Interface Renumbering May Occur After IOS Upgrade to 12.3(6) or 12.3(2)T and Subsequent Releases With a Combination of DSL WIC's and Other WIC's or VWIC's Installed in the Same Chassis

March 21, 2005

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Products Affected

Product	Comments
26xx/36xx/37xx - VWIC-1MFT-E1, VWIC-2MFT-E1, VWIC-2MFT-E1-DI	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - VWIC-1MFT-T1, VWIC-2MFT-T1, VWIC-2MFT-T1-DI	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-1ADSL	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-1DSU-56K4	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-1DSU-T1, WIC-1DSU-T1-V2	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-1SHDSL	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-1T, WIC-2T	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T
26xx/36xx/37xx - WIC-2A/S	for Mainline images starting at 12.3(6) and for T-Train images starting at 12.3(2)T

Problem Description

When upgrading from Cisco IOS® software version 12.3(5d), 12.2(15)T14 or earlier to Cisco IOS software version 12.3(6), 12.3(2)T or later when there is a combination of DSL WICs (WIC-1ADSL and WIC-1SHDSL) and WIC's or VWIC's (WIC-1T or WIC-2T, WIC-2A/S, WIC-1DSU-T1 or WIC-1DSU-T1-V2, WIC-1DSU-56K4, VWIC-1MFT-E1 or VWIC-2MFT-E1 or VWIC-2MFT-E1-DI, VWIC-1MFT-T1 or VWIC-2MFT-T1 or VWIC-2MFT-T1-DI), the interface or port numbering may change after the upgrade and the interface or port configuration may be lost.

Background

Prior to Cisco IOS software version 12.3(6) and 12.3(2)T, the interface numbering scheme for DSL WICs was dependent upon the ATM WICs present on the router. A problem arises when a DSL WIC and a WIC or VWIC (see Products Affected) controller configured in mode atm are present on the same router. These WICs may show up with the same ATM interface numbers.

To address this issue, in Cisco IOS software 12.3(6) and 12.3(2)T, Cisco increases the port number as we discover them from WIC 0 to WIC n. For example on 2600 onboard wic slots, if a T1 VWIC is present on the motherboard WIC slot 0, and a DSL WIC is present in WIC slot 1, the ATM on the DSL WIC will create ATM 0/2, because VWIC-2MFT-T1 is taking up ATM 0/0 and ATM 0/1.

However, with this approach, the combination of WIC-2T and a DSL WIC would result in different interface numbering scheme. If there is a DSL WIC in WIC slot 0 and a WIC-2T in WIC slot 1, the serial interface is getting S0/1 and S0/2 instead of S0/0 and S0/1 because port 0 is taken up by the DSL WIC.

Refer to CSCee78247 for more information.

Problem Symptoms

When upgrading Cisco IOS software from 12.3(5d), 12.2(15)T14 or earlier to Cisco IOS software 12.3(6), 12.3(2)T or later, the interface numbering may change.

Case 1:

Mainboard: slot 0: t1/e1, slot1: SHDSL 
Network Module: slot 0: t1/e1, slot1: ADSL 

Show interfaces & controllers: 
controller T1 0/0 
controller T1 0/1 
controller T1 1/0 
controller T1 1/1 
interface ATM0/2 
interface ATM1/2 

Note: Here the ATM numbering scheme is 0/2 and 1/2 (note the 2 in 0/2 and 1/2) because the controller ports already took 0 and 1 for the T1/E1 WICs present in WIC slot 0.

Case 2:

Mainboard: slot 0: SHDSL, slot1: T1/E1 
Network Module: slot 0: ADSL, slot1: T1/E1 

Show interfaces & controllers: 
controller T1 0/1 
controller T1 0/2 
controller T1 1/1 
controller T1 1/2 
interface ATM0/0 
interface ATM1/0 

Note: Here the interface numbering for the controllers are 0/1, 0/2 and 1/1, 1/2 because the ATM ports already took 0 for the DSL WICs present in WIC slot 0.

If you have a DSL WIC in slot 1 and have some configuration on this WIC (In this case ATM will show up as 0/0), then insert T1/E1 WIC in slot 0, and reload the router. The DSL WICs will show up as ATM 0/2, in which case the previous configurations on DSL WICs are lost.

Workaround/Solution

You must reconfigure the new interface with the old interface configuration.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

DDTS	Description
CSCee78247 (registered customers only)	ADSL ATM interface renumbered after IOS upgrade

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email
• By telephone

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