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New Member

/31 not allowed on ASA

I have just been told that ASAs don't support a /31 assignment on an interface because they don't run IOS. Is this true? Also, can anyone point me at any official documentation stating either way?

All I have found is this [1] which just says "Do Not Use"?

[1] http://www.cisco.com/en/US/docs/security/asa/asa81/config/guide/ports.html#wp1007373

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/31 not allowed on ASA

Hi,

Routers run IOS s/w - mainly provides rich routing capabilities, where as ASA s/w main purpose is 'security' at the perimeter. Both are with different features and functionality. Being said that at this time /31 is not supported on ASA interface ( I do not have 8.4.x version available on our ASAs, but I don't think this version does not support either).

This is just basic. If you google for the diff, you may be able to find alot of discussions on this.

hth

MS

4 REPLIES

/31 not allowed on ASA

New Member

/31 not allowed on ASA

Hi mvshik123,

Thanks for your prompt response

Thats for IOS 12.2, I don't think ASA's run IOS do they? Don't they run their own ASA OS which is IOS "like"?

Many thanks,

/31 not allowed on ASA

Hi,

Routers run IOS s/w - mainly provides rich routing capabilities, where as ASA s/w main purpose is 'security' at the perimeter. Both are with different features and functionality. Being said that at this time /31 is not supported on ASA interface ( I do not have 8.4.x version available on our ASAs, but I don't think this version does not support either).

This is just basic. If you google for the diff, you may be able to find alot of discussions on this.

hth

MS

New Member

/31 not allowed on ASA

Thanks for that mvsheik123. I have found more useful info confirm no /31's

Still thanks for clearing this up

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