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New Member

Why ASA 5520 has subinterfaces

             Hi all,

I am new to ASA  cisco 5520 firewall.

I checked config of ASA  5520 it has subinterfaces on gigabit.

Need to know why we create subinterfaces when it has already 4 lan interfaces?

Thanks

MAhesh    

Everyone's tags (6)
2 ACCEPTED SOLUTIONS

Accepted Solutions
Red

Why ASA 5520 has subinterfaces

Apart from what Kevin said, they are also created if you need the other physical interfaces for some future purpose as well, or if the no. of interfaces that you need is greater than the no. of physical interfaces you have on the ASA.

Thanks,
Varun Rao
Security Team,
Cisco TAC

Thanks, Varun Rao Security Team, Cisco TAC

Re: Why ASA 5520 has subinterfaces

Yes the ASA uses 802.1Q.

Sent from Cisco Technical Support iPhone App

Kind Regards, Kevin Sheahan, CCIE # 41349
5 REPLIES

Why ASA 5520 has subinterfaces

Subintefaces can be created for different VLANs that all come in on one physical port. Like 'Router on a Stick'.

Kind Regards,

Kevin

**Please remember to rate helpful posts as well as mark the question as 'answered' once your issue is resolved. This will help others to find your solution faster.

Kind Regards, Kevin Sheahan, CCIE # 41349
Red

Why ASA 5520 has subinterfaces

Apart from what Kevin said, they are also created if you need the other physical interfaces for some future purpose as well, or if the no. of interfaces that you need is greater than the no. of physical interfaces you have on the ASA.

Thanks,
Varun Rao
Security Team,
Cisco TAC

Thanks, Varun Rao Security Team, Cisco TAC
New Member

Why ASA 5520 has subinterfaces

Hi Varun,

Thanks for reply.

so it means that ASA  also use same trunking protocol like 802.1q same like routers and switches?

MAhesh

Re: Why ASA 5520 has subinterfaces

Yes the ASA uses 802.1Q.

Sent from Cisco Technical Support iPhone App

Kind Regards, Kevin Sheahan, CCIE # 41349
New Member

Why ASA 5520 has subinterfaces

Hi Kevin and Varun,

Many thanks for your replies.

As i am new to ASA and i have to work on it now as my new jon so will ask more questions

Regards

MAhesh

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