Cisco 3845 cannot detect HWIC-4B-S/T

Answered Question
Aug 15th, 2010
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I have just received a Cisco 3845 and I have installed 2 ISDN BRI cards HWIC-4B-S/T. The router has only these cards and a AIM VPN module installed.

The router cannot detect the cards.

I have placed an isdn BRI card  HWIC-S/T ( 1 port ) it detects it without any problem on the same slot HWIC 0 and then HWIC 1 to test if the slots are ok too.

My question is there a problem on the HWIC-4B-S/T cards or any configuration to make.

The documentation says the router 3845 supports the HWIC-4B-S/T cards.

Please advise,

Thanks for your support,

Ashley Dewoo

Correct Answer by Giuseppe Larosa about 6 years 8 months ago

Hello Ashley,

datasheet is here:

it says:

Supported in NM-1FE2W-V2, NM-1FE1R2W, NM-2FE2W-V2, and NM-2W

Can not be inserted into a mixed-media network module

post sh inventory

Hope to help


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Overall Rating: 5 (1 ratings)
ashley_dew Sun, 08/15/2010 - 23:31
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I found the solution,

You need to upgrade to IOS Advanced Services 12.4(20) T for the router to detect the cards.

For some reasons, the ios advanced security 12.4 (23) which i had previously did not support these cards.

Thanks again,



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